-*- mode:outline -*-

* Introduction
==============

This file presents some general information about XEmacs.  It is
primarily about the changes in recent XEmacs versions and its release
history.

Use `C-c C-f' to move to the next equal level of outline, and
`C-c C-b' to move to previous equal level.  `C-h m' will give more
info about the Outline mode.  Many commands are also available through 
the menubar.

Users who would like to know which capabilities have been introduced
in each release should look at the appropriate section of this file.
Starting with version 20.0, XEmacs includes ChangeLogs, which can be
consulted for a more detailed list of changes.

Users interested in some of the details of how XEmacs differs from GNU
Emacs should read the section "What's Different?" near the end of this
file.

    N.B.  The term "GNU Emacs" refers to any release of Emacs Version
    19 from the Free Software Foundation's GNU Project.  (We do not
    say just "Emacs" as Richard M. Stallman ["RMS"] prefers, because
    it is clearly a more generic term.)  The term "XEmacs" refers to
    this program or to its predecessors "Era" and "Lucid Emacs".  The
    predecessor of all these program is called "Emacs 18".  When no
    particular version is implied, "Emacs" will be used.


* Changes in XEmacs 21.0
========================

** XEmacs has been unbundled into constituent installable packages.
See the Info documentation under "Packages" for more information.
See the file `etc/PACKAGES' in the distribution for a partial list of
packages available at the time of the 21.0 release.

IMPORTANT NOTE: XEmacs currently expects the user-specific package
hierarchy in ~/.xemacs.  This will probably change to
~/.xemacs/packages in a future version of XEmacs.

** XEmacs is now supported under Microsoft Windows 95/98 and Windows
NT operating systems.  For starters, look at the XEmacs on Windows FAQ
at <URL:http://jagor.srce.hr/~hniksic/xemacs-on-windows-faq.txt>.  To
discuss Windows-specific issues, subscribe to the mailing list at
<xemacs-nt-request@xemacs.org>.

** XEmacs will now use `XEmacs' as its application class if it finds
any `XEmacs' resources in the resource database.  Otherwise, it will
continue to use the `Emacs' class.

** The options menu has been ported to Custom.
This means that each entry in the options menu acts as if you had customized
the corresponding variable by hand.  ### WARNING: there is currently no
upgrading function to help you port your old options settings to the new
format. Consequently, if you want to modify the options for XEmacs 21, you
will have to set them all again through the menu, and remove the code loading
.xemacs-options from your .emacs.

** When the Zmacs region is active, `M-x query-replace' and the other
replace commands now operate on the region contents only.

** XEmacs now is able to choose X visuals and use private colormaps.
The '-visual <visualStr>' command line option or the '.EmacsVisual'
Xresource controls which visual XEmacs will use, and
'-privateColormap' or '.privateColormap' will force XEmacs to create a
private colormap for use.  The syntax for the visual string is
"<visual><bitdepth>" where <visual> is one of 'StaticColor',
'TrueColor', 'GrayScale', 'PseudoColor' or 'DirectColor' and
<bitdepth> is the appropriate number of bits per pixel.  If an invalid
or non-supported combination is entered, XEmacs attempts to find a happy
medium.  The X creation mechanism will then determine if it needs to
create a colormap for use, or the presence of the private flags will
force it to create it.

** The `imenu' package has been ported to XEmacs and is available as a
package.

** `echo-keystrokes' can now be a floating-point number, so that you
can set it to intervals shorter than one second.

   (setq echo-keystrokes 0.1)

** The new command `center-to-window-line' works like `recenter'
(bound to `C-l'), only it does not redisplay the whole display area.

** The M-. command will now first search through exact tags matches,
and then through inexact matches, as one would expect.

** The new variable `user-full-name' can be used to customize one's
name when using the Emacs mail and news reading facilities.

Normally, `user-full-name' is a function that returns the full name of 
a user or UID, as specified by the system -- for instance,
(user-full-name "root") returns something like "Super-User".  However, 
when the function is called without arguments, it will return the
value of the `user-full-name' variable.  The `user-full-name' variable 
is initialized using the environment variable NAME and (failing that)
the user's system name.

The behaviour of the `user-full-name' function with an argument
specified is unchanged.

** The new command `M-x customize-changed-options' lets you customize
all the options whose default values have changed in recent Emacs
versions.  You specify a previous Emacs version number as argument,
and the command creates a customization buffer showing all the
customizable options whose default values were changed since that
version.

If you don't specify a particular version number argument, then the
customization buffer shows all the customizable options for which
Emacs versions of changes are recorded.

** The new command `add-log-convert' can be used to convert the
old-style (pre-20.3) ChangeLog buffers to new style, for
consistency.  A reminder: if you wish to revert to old-style
ChangeLogs instead, customize the value of `add-log-time-format'
variable.

** The new command `zap-up-to-char' is now available.  It is similar
to `zap-to-char', except that it does not delete the searched-for
character.  It is not bound to a key by default.

** You can now store a number into a register with `C-u NUMBER C-x r n'
REG, increment it by INC with `C-u INC C-x r + REG' (to increment by
one, omit C-u INC), and insert it in the buffer with `C-x r g REG'.
This is useful for writing keyboard macros.

** The M-: command, when given a prefix argument, will now insert its
result to the current buffer.

** The `C-h c' command, when given a prefix argument, will now insert
the message into the current buffer.

** Horizontally split windows may now be dragged using the mouse.
Because of this, the dividers between vertical windows are always
visible.  To turn it off, set `vertical-divider-always-visible-p' to
nil.

** XEmacs/Mule (internationalization) changes.

*** Mule support now works on TTY's.  Use `set-terminal-coding-system'
and `set-keyboard-coding-system' to specify the coding system of your
display and keyboard.

*** Egg/SJ3 input method is now officially supported.  Quail and
Egg/Skk have been available through the generalized Leim since 20.3.

*** Localized Japanese menubars are available if XEmacs is built with
XFONTSET and either the X11 libraries are built with X_LOCALE defined
or the native C libraries support Japanese localization.  This has
been available since 20.3, only it hasn't been announced before.

** Jamie Zawinski's `gdb-highlight' extension is now distributed with
the `debug' package.  gdb-highlight makes most objects printed in a
gdb buffer be mouse-sensitive: as text shows up in the buffer, it is
parsed, and objects which are recognized have context-sensitive
commands attached to them.  To use it, add the following to `.emacs':

  (add-hook 'gdb-mode-hook (lambda () (require 'gdb-highlight)))

** The package popper.el is now included in the edit-utils package.
It has been greatly enhanced with respect to the one once included
with the ilisp package and should work well under XEmacs 21.0.

** Gnuserv changes

*** Like the old 'gnudoit' program. Gnuclient -batch now can read from stdin.

*** Gnuclient -batch no longer breaks off the output at the first LF.

** C mode changes

*** Multiline macros are now handled, both as they affect indentation,
and as recognized syntax.  New syntactic symbol cpp-macro-cont is
assigned to second and subsequent lines of a multiline macro
definition.

*** A new style "user" which captures all non-hook-ified
(i.e. top-level) .emacs file variable setings and customizations.
Style "cc-mode" is an alias for "user" and is deprecated.  "gnu" style
is still the default however.

*** "java" style now conforms to Sun's JDK coding style.

*** There are new commands c-beginning-of-defun, c-end-of-defun which
are alternatives which you could bind to C-M-a and C-M-e if you prefer
them.  They do not have key bindings by default.

*** New and improved implementations of M-a (c-beginning-of-statement)
and M-e (c-end-of-statement).

*** C++ namespace blocks are supported, with new syntactic symbols
namespace-open, namespace-close, and innamespace.

*** File local variable settings of c-file-style and c-file-offsets
makes the style variables local to that buffer only.

*** New indentation functions c-lineup-close-paren,
c-indent-one-line-block, c-lineup-dont-change.

*** Improvements (hopefully!) to the way CC Mode is loaded.  You
should now be able to do a (require 'cc-mode) to get the entire
package loaded properly for customization in your .emacs file.  A new
variable c-initialize-on-load controls this and is t by default.

** In Text mode, now only blank lines separate paragraphs.
This makes it possible to get the full benefit of Adaptive Fill mode
in Text mode, and other modes derived from it (such as Mail mode).
TAB in Text mode now runs the command indent-relative; this makes a
practical difference only when you use indented paragraphs.

As a result, the old Indented Text mode is now identical to Text mode,
and is an alias for it.

If you want spaces at the beginning of a line to start a paragraph,
use the new mode, Paragraph Indent Text mode.

** Changes to Gnus, the XEmacs newsreader.

*** New functionality for using Gnus as an offline newsreader has been
added.  A plethora of new commands and modes have been added.  See the
Gnus manual for the full story.

*** The nndraft backend has returned, but works differently than
before.  All Message buffers are now also articles in the nndraft
group, which is created automatically.

*** `gnus-alter-header-function' can now be used to alter header
values.

*** `gnus-summary-goto-article' now accept Message-ID's.

*** A new Message command for deleting text in the body of a message
outside the region: `C-c C-v'.

*** You can now post to component group in nnvirtual groups with
`C-u C-c C-c'.

*** `nntp-rlogin-program' -- new variable to ease customization.

*** `C-u C-c C-c' in `gnus-article-edit-mode' will now inhibit
re-highlighting of the article buffer.

*** New element in `gnus-boring-article-headers' -- `long-to'.

*** `M-i' symbolic prefix command.  See the section "Symbolic
Prefixes" in the Gnus manual for details.

*** `L' and `I' in the summary buffer now take the symbolic prefix
`a' to add the score rule to the "all.SCORE" file.

*** `gnus-simplify-subject-functions' variable to allow greater
control over simplification.

*** `A T' -- new command for fetching the current thread.

*** `/ T' -- new command for including the current thread in the
limit.

*** `M-RET' is a new Message command for breaking cited text.

*** \\1-expressions are now valid in `nnmail-split-methods'.

*** The `custom-face-lookup' function has been removed.  
If you used this function in your initialization files, you must
rewrite them to use `face-spec-set' instead.

*** Cancelling now uses the current select method.  Symbolic prefix
`a' forces normal posting method.

*** New command to translate M******** sm*rtq**t*s into proper text
-- `W d'.

*** For easier debugging of nntp, you can set `nntp-record-commands'
to a non-nil value.

*** nntp now uses ~/.authinfo, a .netrc-like file, for controlling
where and how to send AUTHINFO to NNTP servers.

*** A command for editing group parameters from the summary buffer
has been added.

*** A history of where mails have been split is available.

*** A new article date command has been added -- `article-date-iso8601'.

*** Subjects can be simplified when threading by setting
`gnus-score-thread-simplify'.

*** A new function for citing in Message has been added --
`message-cite-original-without-signature'.

*** `article-strip-all-blank-lines' -- new article command.

*** A new Message command to kill to the end of the article has
been added.

*** A minimum adaptive score can be specified by using the
`gnus-adaptive-word-minimum' variable.

*** The "lapsed date" article header can be kept continually
updated by the `gnus-start-date-timer' command.

*** Web listserv archives can be read with the nnlistserv backend.

*** Old dejanews archives can now be read by nnweb.

*** Byte-compilation of user-specs now works under XEmacs.

** The `dir' files are no longer essential for functioning of the Info
subsystem.  If the `dir' file does not exist in an Info directory, the
relevant information will be generated on-the-fly.

This behaviour can be customized, look for `Info-auto-generate-directory'
and `Info-save-auto-generated-dir' in the `info' customization group.

** Version Control is no longer automatically loaded.  Users must
add:

(require 'vc-hooks)

to their .emacs file to get version control functionality.

** The EDiff menus are no longer included in the default menubar.
Users must add:

(require 'ediff-hook)

to their .emacs file to get the menus.

** An experimental version of dynamic linking is supported.

There is no documentation and we are making no guarantees about what
might change in the future with the "C" level API.  Examples of how to 
make DLLs are in the modules subdirectory of the XEmacs source
distribution.

Please note that XEmacs is a GPL'ed program and there are restrictions
on what kinds of binaries that can be linked with it.  In particular,
proprietary DLLs without source cannot be distributed.  See the file
COPYING for more details.

* Lisp and internal changes in XEmacs 21.0
==========================================

** There is a new configure option '--with-clash-detection' to
   enable/disable 'lockdir' based clash detection. (Actually, it has
   been there since 20.4, but was not documented then). The
   implementation based on a central locking directory can cause
   severe slowdowns on networked file systems. Therefore the default
   has been changed to build with clash detection disabled, pending
   reimplementation of the feature (most likely compatible with the
   new implementation in recent FSF verions and Interleaf) in an
   upcoming version.

** It is now possible to build XEmacs with support for 31-bit Lisp
integers (normally, Lisp integers are only 28 bits wide on 32-bit
machines.)  Configure with --use-minimal-tagbits to test.  With this
change, the maximum buffer size on 32-bit machines is increased from
128M to 1G.  This setting will be made default in a future XEmacs
version.

** Specifier changes.

*** When instantiating a specifier, the window locale now has a higher
precedence than the buffer locale.  This is because the window locale
is more specific than the buffer locale.

*** The new macro `let-specifier' can be used to temporarily add
specifications to specifiers.  See the documentation for details.

*** The new specifiers `vertical-scrollbar-visible-p' and
`horizontal-scrollbar-visible-p' may be used to control scrollbar
visibility.  Previously, the only way to remove a scrollbar was to set
its size to 0.  This method is still supported for backward
compatibility.

*** The new specifiers `scrollbar-on-left-p' and `scrollbar-on-top-p'
may be used to control the position of the vertical and horizontal
toolbar.  Previously, their position could be changed only through the
use of X resources.

*** The new draggable vertical dividers between windows may be turned
off using the `vertical-divider-always-visible-p' specifier.  When
this is set to nil, the vertical dividers between windows are shown
only when needed, and they are not draggable.

Other properties of the vertical dividers may be controlled using
`vertical-divider-shadow-thickness', `vertical-divider-line-width' and 
`vertical-divider-spacing' specifiers, which see.

** Frame focus management changes.

*** When the variable focus-follows-mouse is non-nil, `select-frame'
no longer permanently selects a different frame.  The frame selection
is temporary and is reverted when the current command terminates, much
like the buffer selected by `set-buffer'.  This is the same as in FSF
Emacs.

*** The new function `focus-frame' sets the window system focus to
FRAME (and selects it), regardless of the value of
`focus-follows-mouse'.  Doing this is not well behaved, so be
absolutely sure that you want this.

The code that uses `select-frame' only to get the window manager focus
should be changed to use `set-frame-focus' instead, so that they keep
working when `focus-follows-mouse' is non-nil.

*** The special forms `save-selected-frame' and `with-selected-frame'
can now be used to temporarily change selected frame.

*** The behavior of `other-frame' command (`C-x 5 o') is unaffected by
these changes.

** The function `select-window' now has an optional second argument
NORECORD which if non-nil inhibits the recording of a buffer change.

** The function `vertical-motion' now correctly handles the second,
optional WINDOW argument.  A new third argument PIXELS, if non-nil,
indicates that the returned motion should be in pixels.

** The new function `vertical-motion-pixels' is similar to
vertical-motion but takes as input a vertical motion in pixels.

** The new functions window-text-area-pixel-{width,height,edges} can
be used to obtain information about the text-displaying area of a
window.

** The new functions `shrink-window-pixels' and `enlarge-window-pixels'
can be used to adjust the size of a window by a pixel amount.

** The new function `window-displayed-text-pixel-height' can be used
to determine the height of the text actually displayed in a window.

** The arithmetic comparison functions <, >, =, /= now accept a
variable number of arguments.

This means that if you want to test whether A < B < C, you can write
it as (< A B C) instead of (and (< A B) (< B C)).  Likewise,
(apply #'> LIST) now tests if LIST is monotonically increasing -- and
so on.

** The XEmacs hashtables now have a consistent read/print syntax.
This means that a hashtable will be readably printed in a
structure-like form:

   #s(hashtable size 2 data (key1 value1 key2 value2))

When XEmacs reads this form, it will create a new hashtable according
to description.  This allows you to easily dump hashtables to files
using `prin1', and read them back in using `read'.

If `print-readably' is non-nil, a more relaxed syntax is used; for
instance:

   #<hashtable size 2/13 data (key1 value1 key2 value2) 0x874d>

** It is now possible to build XEmacs with LDAP support.
You will need to install a LDAP library first.  The following have
been tested:
  - LDAP 3.3 from the University of Michigan 
    (get it from <URL:http://www.umich.edu/~dirsvcs/ldap/>)
  - OpenLDAP 1.0.3 from the OpenLDAP Foundation
    (get it from <URL:http://www.openldap.org/>)
  - LDAP SDK 1.0 from Netscape Corp.
    (get it from <URL:http://developer.netscape.com/>)

** When profiling is in effect, a call-count of all recorded functions
is now calculated.  This information is stored in
`call-count-profile-table', and is utilized by `profile-results' as
well as the new command `profile-call-count-results'.

** It is now an error to change the value of a symbol whose name
starts with a colon, if it is interned in the standard obarray.

However, setting such a symbol to its proper value, which is that
symbol itself, is not an error.  This is for the sake of programs that
support pre-19.12 XEmacs and pre-20 GNU Emacs by explicitly setting
these variables to themselves.

** The `concat' function no longer accepts integer arguments.

** The new function `string' concatenates all its argument characters
and returns the resulting string.  This is consistent with other
functions, like `list', `vector', etc.

** The function `temp-directory' is now available to return the
directory to store temporary files.  On Unix this will be obtained
from TMPDIR, defaulting to `/tmp'.

** The function load-average now accepts an optional argument
USE-FLOATS.  If it is non-nil, the load average values are returned as
floating point numbers, rather than as integers to be divided by 100.

** The `make-event' function now supports the TYPE and PLIST
arguments, which can be used to create various events from Lisp.  See
the documentation for details.

** `function-interactive' is a new function that returns the
interactive specification of a funcallable object.

** The new `lmessage' function allows printing of a formatted message
with a particular label.

   (lmessage 'progress "Processing... %d" counter)

This function is more convenient than `display-message' because it
automatically applies `format' to its arguments.

** The new `lwarn' function, analogous to `lmessage', allows printing
a formatted warning, with a non-default CLASS or LABEL.

** The new function `split-path' can now be used to explode the
components of a colon-separated search path into a list.

   (split-path "foo:bar")
     => ("foo" "bar")

** Specifiers and symbols whose value is a specifier are now allowed
as modeline specifications.

** defcustom now accepts the keyword `:version'.  Use this to specify
in which version of Emacs a certain variable's default value changed.
For example,

   (defcustom foo-max 34 "*Maximum number of foo's allowed."
     :type 'integer
     :group 'foo
     :version "21.0")

This information is used to control the customize-changed-options
command.

** The line number tracking in modeline is now efficient, even for
very large buffers.  This is achieved by caching the line numbers of
recent buffer positions, and reusing them.  This cache is used only in
the buffers where `line-number-mode' is in effect.

** When the new GNU Malloc aka Doug Lea Malloc is available, it will
be used.  This should result in better performance on Linux systems
with libc6.

** The code XEmacs uses to assemble its various paths into the
directory hierarchy has been rewritten to support the package system.
Look under "Startup Paths" in the Info documentation for more
information.

*** site-lisp is no longer part of the load-path by default.
Its use is deprecated, but you can specify --with-site-lisp=yes at the
configure command line to get it back.

*** `Info-default-directory-list' is now obsolete.  If you want to
change the path which XEmacs uses to search for info files, set
`Info-directory-list' instead.


* Changes in XEmacs 20.4
========================

** XEmacs 20.4 is a bugfix release with no user-visible changes.


* Changes in XEmacs 20.3
========================

** Quail input method is now available.

Quail is a simple key-translation system that allows users to input
any multilingual text from normal ASCII keyboard.  This means that
XEmacs with Mule now supports a number of European languages.

** More Windows NT support.

Thanks to efforts of many people, coordinated by David Hobley
<davidh@wr.com.au> and Marc Paquette <marcpa@cam.org>, beta versions
of XEmacs now run on 32-bit Windows platforms (Windows NT and Windows
95).  The current betas require having an X server to run XEmacs;
however, a native NT/95 port is in alpha, thanks to Jonathan Harris
<jhar@tardis.ed.ac.uk>.

The NT development is now coordinated by a mailing list at
<xemacs-nt@xemacs.org>.  Mail to <xemacs-nt-request@xemacs.org> to
subscribe.

** Multiple TTY frames are now available.

On consoles that display only one frame at a time (e.g. TTY consoles),
creating a new frame with `C-x 5 2' also raises and selects that
frame.  The behavior of window system frames is unchanged.

** Package starting changes.

State of Emacs should never be changed with loading a package.  The
following XEmacs packages that used to break this have been changed.

*** Loading `paren' no longer enables paren-blinking.  Use
`paren-set-mode' explicitly, or customize `paren-mode'.

*** Loading `uniquify' no longer enables uniquify.  Set
`uniquify-buffer-name-style' to a legal value.

*** Loading `time' no longer enables display time.  Invoke
`display-time' explicitly.

*** Loading `jka-compr' no longer enables on-the-fly compression.  Use
`toggle-auto-compression' instead.

*** Loading `id-select' no longer enables its behaviour.  Use
`id-select-install' instead.

** Zmacs region is not deactivated when an error is signaled.

The behavior of the zmacs region can now be controlled in the event of
a signaled error.  The new variable `errors-deactivate-region' may be
set to nil to revert to the old behaviour.  As before, typing C-g
deactivates the region.

** Multiple Info `dir' functionality has been merged with GNU Emacs
19.34.

XEmacs will now correctly merge all the `dir' files in
`Info-directory-list' (initialized from either the `INFOPATH'
env. variable or `Info-default-directory-list'.)  These files may be
full-fledged info files containing subnodes or menus.  Previously
supported `localdir' files are looked for also, secondary to `dir's.
See the manual for details.

** Abbreviations can now contain non-word characters.

This means that it is finally possible to do such simple things as
define `#in' to expand to `#include' in C mode, `s-c-b' to
`save-current-buffer' in Lisp mode, `call/cc' to
`call-with-current-continuation' in Scheme mode, etc.

** `C-x n d' now runs the new command `narrow-to-defun',
which narrows the accessible parts of the buffer to just
the current defun.

** The new command `C-x 4 0' (kill-buffer-and-window) kills the
current buffer and deletes the selected window.  It asks for
confirmation first.

** `ESC ESC ESC' (keyboard-escape-quit) will now correctly abort
recursive edits (as documented.)

** arc-mode has a new function called `archive-quit' bound to q, which
quits archive mode in the same fashion dired-quit works.

** A `tetris' clone is now available within XEmacs, written by Glynn
Clements.  Try it out with `M-x tetris'.
 
** The feature to teach the key bindings of extended commands now
prints the message after the command finishes.  After some time, the
previous echo area contents are restored (in case the command prints
something useful).

** If you set scroll-conservatively to a small number, then when you
move point a short distance off the screen, XEmacs will scroll the
screen just far enough to bring point back on screen, provided that
does not exceed `scroll-conservatively' lines.

** Face background colors now take precedence over the default face
background pixmap, which means that background pixmaps no longer clash
with zmacs-regions, or clickable buttons.

** Regexps can now contain additional Perl-like constructs.

** Modifiers can be added to a keystroke by preceding it with a `C-x @
<x>' sequence where <x> is one of letters `S', `c', `m', `a', `h', `s'
corresponding to shift, control, meta, alt, hyper, and super modifiers,
respectively.  It is possible to add several modifiers by repeating this
sequence.  This feature is especially useful on text terminals where it
allows one to enter keystrokes like, e.g., `M-home'.

** An arbitrary keystroke can be generated by entering `C-x @ k
<keysym-name> RET'.  For example a sequence:

  C-x @ c C-x @ k b a c k s p a c e RET

will result in a `C-backspace' keystroke even on text terminals.

** Customize changes.

*** Customize has undergone a massive speedup, and should now operate
acceptably fast.  Slowness of the interface used to be the biggest
gripe.

*** Many more packages have been modified to use the facility, so
almost all of XEmacs options can now be examined through the Customize
groups.

*** There is a new `browser' mode of traversing customizations, in
many ways easier to follow than the standard one.  Try it out with
`M-x customize-browse'.

** Pending-delete changes.

*** Pending-delete is now a minor mode, with the normal minor-mode
semantics and toggle functions.  Old functions are left for
compatibility.

*** Loading pending-del no longer turns on pending-delete mode.  In
fact, it is no longer necessary to explicitly load pending-del.  All
you need to do to turn on pending-delete is run the pending-delete
function:

  Within XEmacs:   Type      M-x pending-delete <ret>
                    not      M-x load-library <ret> pending-delete <ret>
  
  In .emacs:       Use       (turn-on-pending-delete)
                   not       (load "pending-del")

** XEmacs can now save the minibuffer histories from various
minibuffers.  To use this feature, add the line:

   (savehist-load)

to your .emacs.  This will load the minibuffer histories (if any) at
startup, as well as instruct XEmacs to save them before exiting.  You
can use Customize to add or remove the histories being saved.

** The default format for ChangeLog entries (as created by `C-x 4 a')
is now the international ISO 8601 format.

To revert to the old behaviour, use:

   (setq add-log-time-format 'current-time-string)

Or `M-x customize RET add-log RET'.

** In ChangeLog mode, you can now press `C-c C-c' to save the file
and restore old window configuration, or `C-c C-k' to abandon the
changes.

** The key `C-x m' no longer runs the `mail' command directly.
Instead, it runs the command `compose-mail', which invokes the mail
composition mechanism you have selected with the variable
`mail-user-agent'.  The default choice of user agent is
`sendmail-user-agent', which gives behavior compatible with the old
behavior.

C-x 4 m now runs compose-mail-other-window, and C-x 5 m runs
compose-mail-other-frame.

** When you kill a buffer that visits a file, if there are any
registers that save positions in the file, these register values no
longer become completely useless.  If you try to go to such a register
with `C-x j', then you are asked whether to visit the file again.  If
you say yes, it visits the file and then goes to the same position.

** When you visit a file that changes frequently outside Emacs--for
example, a log of output from a process that continues to run--it may
be useful for Emacs to revert the file without querying you whenever
you visit the file afresh with `C-x C-f'.

You can request this behavior for certain files by setting the
variable revert-without-query to a list of regular expressions.  If a
file's name matches any of these regular expressions, find-file and
revert-buffer revert the buffer without asking for permission--but
only if you have not edited the buffer text yourself.

** Gnuserv changes

*** The Lisp part of gnuserv has been rewritten to allow for more
flexibility and features.

*** Many new options and variables are now customizable.  Try
`M-x customize RET gnuserv RET'.

*** The functionality of `gnuattach' and `gnudoit' programs is
provided by `gnuclient', which now accepts the standard `-nw',
`-display', `-eval' and `-f' options.

** Etags changes.

*** In C, C++, Objective C and Java, Etags tags global variables by
default.  The resulting tags files are inflated by 30% on average.
Use --no-globals to turn this feature off.  Etags can also tag
variables that are members of structure-like constructs, but it does
not by default.  Use --members to turn this feature on.

*** C++ member functions are now recognized as tags.

*** Java is tagged like C++.  In addition, "extends" and "implements"
constructs are tagged.  Files are recognised by the extension .java.

*** Etags can now handle programs written in Postscript.  Files are
recognised by the extensions .ps and .pdb (Postscript with C syntax).
In Postscript, tags are lines that start with a slash.

*** Etags now handles Objective C and Objective C++ code.  The usual C and
C++ tags are recognized in these languages; in addition, etags
recognizes special Objective C syntax for classes, class categories,
methods and protocols.

*** Etags also handles Cobol.  Files are recognised by the extension
.cobol.  The tagged lines are those containing a word that begins in
column 8 and ends in a full stop, i.e. anything that could be a
paragraph name.

*** Regexps in Etags now support intervals, as in ed or grep.  The syntax of
an interval is \{M,N\}, and it means to match the preceding expression
at least M times and as many as N times.

** Ada mode changes.

*** There is now better support for using find-file.el with Ada mode.
If you switch between spec and body, the cursor stays in the same
procedure (modulo overloading).  If a spec has no body file yet, but
you try to switch to its body file, Ada mode now generates procedure
stubs.

*** There are two new commands:
 - `ada-make-local'   : invokes gnatmake on the current buffer
 - `ada-check-syntax' : check syntax of current buffer.

The user options `ada-compiler-make', `ada-make-options',
`ada-language-version', `ada-compiler-syntax-check', and
`ada-compile-options' are used within these commands. 

*** Ada mode can now work with Outline minor mode.  The outline level
is calculated from the indenting, not from syntactic constructs.
Outlining does not work if your code is not correctly indented.

*** The new function `ada-gnat-style' converts the buffer to the style of
formatting used in GNAT.  It places two blanks after a comment start,
places one blank between a word end and an opening '(', and puts one
space between a comma and the beginning of a word.

** New demand based locking implementation

A faster, but experimental replacement for lazy-lock (called lazy-shot) is
provided.  Like lazy-lock it provides demand based and idle time
font-lock-ing.  However the lazy-lock versions that came with previous
versions slowed down XEmacs (possibly quite a lot).  Lazy-shot solves
this problem by relying on new support from the C code part of XEmacs.
The support however is experimental and will cause some flashing as
parts of the buffer are colored.  This likely to change in the future
as the C support is completed. 

The current lazy-shot implementation is mostly interface compatible
with lazy-lock v2.06 (the version shipped with XEmacs is v1.x).

*** To enable:
 1. Despite the flashing, lazy-shot was deemed such an improvement by
    the majority of beta testers that it is now the standard method
    provided by the options menu. Alternatively add

	(add-hook 'font-lock-mode-hook 'turn-on-lazy-shot)

    to '.emacs'.	
 2. If you were using lazy-lock before, just replace all occurrences of 
    "lazy-lock" by "lazy-shot" in your '.emacs' file.

*** To disable:

If prefer to use lazy-lock in stead of lazy-shot, put

	(remove-hook 'font-lock-mode-hook 'turn-on-lazy-shot)
	(add-hook 'font-lock-mode-hook 'turn-on-lazy-lock)

at the END of `.emacs'.

** RefTeX mode

RefTeX mode is a new minor mode with special support for \label{}, \ref{}
and \cite{} macros in LaTeX documents.  RefTeX distinguishes labels of
different environments (equation, figure, ...) and has full support for
multifile documents.  To use it, select a buffer with a LaTeX document and
turn the mode on with M-x reftex-mode.  Here are the main user commands:

C-c (    reftex-label        
   Creates a label semi-automatically.  RefTeX is context sensitive and
   knows which kind of label is needed.

C-c )    reftex-reference
   Offers in a menu all labels in the document, along with context of the
   label definition.  The selected label is referenced as \ref{LABEL}.

C-c [    reftex-citation
   Prompts for a regular expression and displays a list of matching BibTeX
   database entries.  The selected entry is cited with a \cite{KEY} macro.

C-c &    reftex-view-crossref
   Views the cross reference of a \ref{} or \cite{} command near point.

C-c =    reftex-toc
   Shows a table of contents of the (multifile) document.  From there you
   can quickly jump to every section.
 
Under X, RefTeX installs a "Ref" menu in the menu bar, with additional
commands.  Full documentation and customization examples are in the file
reftex.el.  You can use the finder to view this information:
C-h p --> tex --> reftex.el


* Lisp and internal changes in XEmacs 20.3
==========================================

** Autoconf 2 is supported, making XEmacs more conforming to
conventions used by other free software.

** `tty-erase-char' is a new variable that reports which character
was set up as the terminal's erase character at the time Emacs was
started.

** It is now possible to attach the menubar accelerator keys to menu
entries.  Look at the Lispref under Menus->Menu Accelerators for
details.

** `insert-file-contents' can now read from a special file,
as long as the arguments VISIT and REPLACE are nil.

** `string-to-number' now accepts an optional BASE argument that
specifies which base to use.  The default base is 10.

** The TIME argument to `format-time-string' is now optional and
defaults to the current time.

** The PATTERN argument to `split-string' is now optional and defaults
to whitespace ("[ \f\t\n\r\v]+").

** `set-extent-properties' is a new function that can be used to
change properties of an extent at once, and is analogous to
`set-frame-properties'.

** If a format field width is specified as `*', the field width is
now assumed to have been specified as an argument (as in C.)

  (format "%*s" 10 "abc")
    => "       abc"

** The new macro `with-current-buffer' lets you evaluate an expression
conveniently with a different current buffer.  It looks like this:

  (with-current-buffer BUFFER BODY-FORMS...)

BUFFER is the expression that says which buffer to use.
BODY-FORMS say what to do in that buffer.
The old `eval-in-buffer' macro is obsoleted by `with-current-buffer'.

** The new primitive `save-current-buffer' saves and restores the
choice of current buffer, like `save-excursion', but without saving or
restoring the value of point or the mark.  `with-current-buffer'
works using `save-current-buffer'.

** The new macro `with-temp-file' lets you do some work in a new buffer and
write the output to a specified file.  Like `progn', it returns the value
of the last form.

** The variable `debug-ignored-errors' now works in XEmacs.  It allows
one to ignore the debugger for some common errors, even when
`debug-on-error' is t.  It has no effect when `debug-on-signal' is
non-nil.

** The new function `current-message' returns the message currently
displayed in the echo area, or nil if there is none.

** File-access primitive functions no longer discard an extra redundant
directory name from the beginning of the file name.  In other words,
they no longer do anything special with // or /~.  The same goes for
`expand-file-name'.  That conversion is now done only in
`substitute-in-file-name'.

This makes it possible for a Lisp program to open a file whose name
begins with ~.

** The regexp matcher has been extended to recognize the following
constructs, borrowed from Perl:

*** Additional quantifiers.

In addition to `*', `+' and `?', XEmacs now recognizes the following
quantifiers:

  \{n\}    Match exactly n times
  \{n,\}   Match at least n times
  \{n,m\}  Match at least n but not more than m times

*** Non-greedy quantifiers.

Any of the standard quantifiers (`*', `+' and others) can now be
followed by an optional `?', which will make them become "non-greedy", 
i.e. they will match as little text as possible.  Note that the
meanings don't change, just the "gravity."

*** Shy groups.

The \(?: ... \) groups things like \( ... \), but doesn't record the
context for backreferences or future use.  This is useful when you
need a lot of groups for the sake of priorities, but actually want to
record only one or two.

** The new function `regexp-opt' returns an efficient regexp to match
a string.  The arguments are STRINGS and (optionally) PAREN.  This
function can be used where regexp matching or searching is intensively
used and speed is important, e.g., in Font Lock mode.

** The featurep syntax has been extended to resemble the Common Lisp
one, as suggested by Erik Naggum.

*** The `xemacs' feature is defined in XEmacs by default.

*** The expression `#+fexp form' is equivalent to
(when (featurep fexp) form), only it is evaluated at read-time.  Also,
`#-fexp form' is equivalent to (unless (featurep fexp) form).

*** In addition to symbols, a FEXP can also be a number, or a logical
operator.  Here are some examples:
  ;; evaluates to non-nil on XEmacs:
  (featurep 'xemacs)
  ;; evaluates to non-nil on XEmacs 20.3 or later:
  (featurep '(and xemacs 20.03))
  ;; evaluates to non-nil either on Emacs, or on XEmacs built without
  ;; X support:
  (featurep '(or emacs (and xemacs (not x))))



* Changes in XEmacs 20.2
========================

** Why XEmacs 20.1 is called 20.2

Testing of XEmacs 20.1 revealed a number of showstopping bugs at the
very final moment.  Instead of confusing the version numbers further,
the `20.1' designation was abandoned, and the release was renamed to
`20.2'.

** Delete/backspace keysyms have been separated

The Delete and Backspace keysyms are now no longer identical.  A better
version of delbackspace.el has been added called delbs.el.

** XEmacs 20.0 MULE API supported for backwards compatibility

XEmacs 20.2 primarily supports the MULE 3 API.  It now also supports
the XEmacs 20.0 MULE API.

** The logo has been changed, and the default background color is
now a shade of gray instead of the eye-burning white.

The sample .Xdefaults and .emacs files contain examples of how to
revert to the old background color.

** Default modeline colors are now less of a color-salad.

** The `C-z' key now iconifies only the current X frame.  You can use
`C-x C-z' to get the old behavior.

On the tty frames `C-z' behaves as before.

** The command `display-time' now draws a pretty image in the modeline
when new mail arrives.  It also supports balloon-help messages.

** Various commands that were previously disabled are now enabled, like
eval-expression (`M-:') and upcase-region (`C-x C-u')/downcase-region
(`C-x C-l').

** It is now possible to customize the functions called by XEmacs toolbar.

Type `M-x customize RET toolbar RET' to customize it.  Customizations
include the choice of functions for the buttons to invoke, as well as
a wide choice of mailers and newsreaders to invoked by the respective
functions.

** `temp-buffer-shrink-to-fit' now defaults to nil.

There are unresolved issues regarding this feature, which is why the
XEmacs developers decided to disable it by default.

** `ps-print-color-p' now defaults to nil.

This is because the new default background color is non-white.  The
`Printing Options' in the `Options' menu now include an item that
enables color printing, and sets the white background.

** `line-number-mode' should be used to get line numbers in the
modeline, and `column-number-mode' to get column numbers.  Line
numbers now number from 1 by default.

** font-lock-mode will now correctly fontify `int a, b, c;'
expressions in C mode.

** The blinking cursor is always "on" during movement.

** The XEmacs build process has been changed to make site
administration easier.  See lisp/site-load.el for details.

** Numerous causes of crashes have been fixed.  XEmacs should now be
even more stable than before.

** configure no longer defaults to using --with-xim=motif if Motif libraries
are linked.

There are many bugs in the Xlib XIM support in X11R6.3.

** A number of new packages are added, and many packages were
updated.

** Gnus-5.4.52, courtesy of Lars Magne Ingebrigtsen

*** nntp.el has been totally rewritten in an asynchronous fashion.

*** Article prefetching functionality has been moved up into 
Gnus.  

*** Scoring can now be performed with logical operators like 
`and', `or', `not', and parent redirection.

*** Article washing status can be displayed in the
article mode line.

*** gnus.el has been split into many smaller files.

*** Suppression of duplicate articles based on Message-ID.

(setq gnus-suppress-duplicates t)

*** New variables for specifying what score and adapt files
are to be considered home score and adapt files.  See
`gnus-home-score-file' and `gnus-home-adapt-files'.

*** Groups can inherit group parameters from parent topics.

*** Article editing has been revamped and is now usable.

*** Signatures can be recognized in more intelligent fashions.
See `gnus-signature-separator' and `gnus-signature-limit'.

*** Summary pick mode has been made to look more nn-like.
Line numbers are displayed and the `.' command can be
used to pick articles.

*** Commands for moving the .newsrc.eld from one server to
another have been added.

    `M-x gnus-change-server'

*** A way to specify that "uninteresting" fields be suppressed when
generating lines in buffers.

*** Several commands in the group buffer can be undone with
`M-C-_'.

*** Scoring can be done on words using the new score type `w'.

*** Adaptive scoring can be done on a Subject word-by-word basis:

    (setq gnus-use-adaptive-scoring '(word))

*** Scores can be decayed.
 
    (setq gnus-decay-scores t)

*** Scoring can be performed using a regexp on the Date header.  The
Date is normalized to compact ISO 8601 format first.

*** A new command has been added to remove all data on articles from
the native server.

   `M-x gnus-group-clear-data-on-native-groups'

*** A new command for reading collections of documents
(nndoc with nnvirtual on top) has been added -- `M-C-d'.

*** Process mark sets can be pushed and popped.

*** A new mail-to-news backend makes it possible to post
even when the NNTP server doesn't allow posting.

*** A new backend for reading searches from Web search engines
(DejaNews, Alta Vista, InReference) has been added.

    Use the `G w' command in the group buffer to create such
    a group.

*** Groups inside topics can now be sorted using the standard
sorting functions, and each topic can be sorted independently.

    See the commands under the `T S' submap.

*** Subsets of the groups can be sorted independently.

    See the commands under the `G P' submap.

*** Cached articles can be pulled into the groups.
  
    Use the `Y c' command.

*** Score files are now applied in a more reliable order.

*** Reports on where mail messages end up can be generated.

    `M-x nnmail-split-history'

*** More hooks and functions have been added to remove junk
from incoming mail before saving the mail.
 
    See `nnmail-prepare-incoming-header-hook'.

*** The nnml mail backend now understands compressed article files.

** Custom 1.86, courtesy of Per Abrahamsen

The Customize library enables Emacs Lisp programmers to specify types
of their variables, so that the users can customize them.

Invoke the customizations buffer using the menus (Customize is at the
top of the Options menu), or using commands `M-x customize',
`M-x customize-variable' and `M-x customize-face'.  Customize can save
the changed settings to your `.emacs' file.

Customize is now the preferred way to change XEmacs settings.  Tens of
packages have been converted to take advantage of the Customize
features, including Gnus, Message, Supercite, Psgml, Comint, W3,
cc-mode (and many other programming language modes), ispell.el,
ps-print.el, id-select.el, most of the programming language modes, and
many many more.

See the "Lisp Changes" section later for a short description of why
and how to add custom support to your Lisp packages.  Custom is also
documented in the XEmacs info manuals.

** W3-3.0.86, courtesy of William Perry

Version 3 of Emacs/W3, the Emacs World Wide Web browser, has been
included.  It is significantly faster than any of the previous
versions, and contains numerous new features.

** AUCTeX-9.7k, courtesy of Per Abrahamsen

AUC TeX is a comprehensive customizable integrated environment for
writing input files for LaTeX using Emacs.

AUC TeX lets you run TeX/LaTeX and other LaTeX-related tools, such as
a output filters or post processor from inside Emacs.  Especially
`running LaTeX' is interesting, as AUC TeX lets you browse through the
errors TeX reported, while it moves the cursor directly to the
reported error, and displays some documentation for that particular
error.  This will even work when the document is spread over several
files.

AUC TeX automatically indents your `LaTeX-source', not only as you
write it -- you can also let it indent and format an entire document.
It has a special outline feature, which can greatly help you `getting
an overview' of a document.

Apart from these special features, AUC TeX provides an large range of
handy Emacs macros, which in several different ways can help you write
your LaTeX documents fast and painless.

** redo.el-1.01, courtesy of Kyle Jones

redo.el is a package that implements true redo mechanism in XEmacs
buffers.  Once you load it from your `.emacs', you can bind the `redo'
command to a convenient key to use it.

Emacs' normal undo system allows you to undo an arbitrary number of
buffer changes.  These undos are recorded as ordinary buffer changes
themselves.  So when you break the chain of undos by issuing some
other command, you can then undo all the undos.  The chain of recorded
buffer modifications therefore grows without bound, truncated only at
garbage collection time.

The redo/undo system is different in two ways:

*** The undo/redo command chain is only broken by a buffer modification.

You can move around the buffer or switch buffers and still come back
and do more undos or redos.

*** The `redo' command rescinds the most recent undo without
recording the change as a _new_ buffer change.

It completely reverses the effect of the undo, which includes making
the chain of buffer modification records shorter by one, to counteract
the effect of the undo command making the record list longer by one.

** edmacro.el-3.10, courtesy of Dave Gillespie, ported to XEmacs by
Hrvoje Niksic.

Edmacro is a utility that provides easy editing of keyboard macros.
Originally written by Dave Gillespie, it has been mostly rewritten by
Hrvoje Niksic, in order to make it distinguish characters and integer,
as well as to adapt it to XEmacs keysyms.

Press `C-x C-k' to invoke the `edit-kbd-macro' command that lets you
edit old as well as define new keyboard macros.  You can also edit the
last 100 keystrokes and insert them into a macro to be bound to a key
or named as a command.  The recorded/edited macros can be dumped to
`.emacs' file.

** xmine.el-1.8, courtesy of Jens Lautenbacher

XEmacs now includes a minesweeper game with a full-featured graphics
and mouse interface.  Invoke with `M-x xmine'.

** efs-1.15-x5 courtesy of Andy Norman and Michael Sperber

EFS is now integrated with XEmacs, and replaces the old ange-ftp.  It
has many more features, including info documentation, support for many
different FTP servers, and integration with dired.

** mic-paren.el-1.3.1, courtesy of Mikael Sjödin
** hyperbole-4.022, courtesy of Bob Weiner
** hm--html-menus-5.3, courtesy of Heiko Muenkel
** python-mode.el-2.90, courtesy of Barry Warsaw
** balloon-help-1.06, courtesy of Kyle Jones
** xrdb-mode.el-1.21, courtesy of Barry Warsaw
** igrep.el-2.56, courtesy of Kevin Rodgers
** frame-icon.el, courtesy of Michael Lamoureux and Bob Weiner
** itimer.el-1.05, courtesy of Kyle Jones
** VM-6.30, courtesy of Kyle Jones
** OO-Browser-2.10, courtesy of Bob Weiner
** viper-2.93, courtesy of Michael Kifer
** ediff-2.65, courtesy of Michael Kifer
** detached-minibuf-1.1, courtesy of Alvin Shelton
** whitespace-mode.el, courtesy of Heiko Muenkel
** winmgr-mode.el, courtesy of David Konerding, Stefan Strobel & Barry Warsaw
** fast-lock.el-3.11.01, courtesy of Simon Marshall
** lazy-lock.el-1.16, courtesy of Simon Marshall
** browse-cltl2.el-1.1, courtesy of Holger Schauer
** eldoc.el-1.10, courtesy of Noah Friedman
** tm-7.105, courtesy of MORIOKA Tomohiko
** verilog-mode.el-2.25, courtesy of Michael McNamara & Adrian Aichner
** overlay.el, courtesy of Joseph Nuspl
** live-icon.el-1.3, fixes courtesy of Karl Hegbloom
** tpu-edt.el, fixes courtesy of R. Kevin Oberman
** etags.c-11.86 Courtesy of F. Potortì


* Lisp and internal changes in XEmacs 20.2
==========================================

** `defcustom' and `defgroup' can now be used to specify types and
placement of the user-settable variables.

You can now specify the types of user-settable variables in your Lisp
packages to be customized by users.  To do so, use `defcustom' as a
replacement for `defvar'.

For example, the old declaration:

(defvar foo-blurgoze nil
  "*non-nil means that foo will act very blurgozely.")

can be rewritten as:

(defcustom foo-blurgoze nil
  "*non-nil means that foo will act very blurgozely."
  :type 'boolean
  :group 'foo)

From a package writer's point of view, nothing has been changed
However, the user can now type `M-x customize RET foo-blurgoze RET' to
customize the variable.

Other, more complex data structures can be described with `defcustom'
too, for instance:

(defcustom foo-hairy-alist '((somekey . "somestring")
                             (otherkey . (foo-doit))
                             (thirdkey . [1 2 3]))
"*Alist describing the hairy options of the foo package.
The CAR of each element is a symbol, whereas the CDR can be either a
string, a form to evaluate, or a vector of integers.
New Emacs users simply adore alists like this one."
  :type '(repeat (cons (symbol :tag "Key")
                       (choice string
                               (vector (repeat :inline t integer))
                               sexp)))
  :group 'foo)

The user will be able to add and remove the entries to the list in a
visually appealing way, as well as save the settings to his/her
`.emacs'.

Note that `defcustom' will also be included in GNU Emacs 19.35, and
that both XEmacs and GNU Emacs will be using it in the future.
Although the user-interface of customize may change, the Lisp
interface will remain the same.  This is why we recommend that you use
`defcustom' for user-settable variables in your new Lisp packages.

** The `read-kbd-macro' function is now available.

The `read-kbd-macro' function (as well as the read-time evaluated
`kbd' macro) from the edmacro package is now available in XEmacs.  For
example:

(define-key foo-mode-map (kbd "C-c <up>") 'foo-up)

is completely equivalent to

(define-key foo-mode-map [(control ?c) up] 'foo-up)

The `kbd' macro is preferred over `read-kbd-macro' function , as it
evaluates before compiling, thus having no loading overhead.

Using `kbd' is not necessary for GNU Emacs compatibility (GNU Emacs
supports the XEmacs-style keysyms), but adds to clarity.  For example,
(kbd "C-?") is usually easier to read than [(control ??)].  The full
description of the syntax of keybindings accepted by `read-kbd-macro'
is documented in the docstring of `edmacro-mode'.

** Overlay compatibility is implemented.

The overlay support in XEmacs is now functional.  Written by Joe
Nuspl, the overlay compatibility library overlay.el is implemented on
top of the native XEmacs extents, and can be used as a GNU
Emacs-compatible way of changing display properties.

** You should use keysyms kp-* (kp-1, kp-2, ..., kp-enter etc.)
rather than the old form kp_*.  The new form is also compatible with
GNU Emacs.

** The keysyms mouse-1, mouse-2, mouse-3 and down-mouse-1,
down-mouse-2, and down-mouse-3 have been added for GNU Emacs
compatibility.

** A new user variable `signal-error-on-buffer-boundary' has been
added.

Set this to variable to nil to avoid XEmacs usual lossage of zmacs
region when moving up against a buffer boundary.

** lib-complete.el was MULE-ized.

The commands `find-library', `find-library-other-window' and
`find-library-other-frame' now take an optional coding system
argument.

** Experimental support for Lisp reader macros #-, #+.

The Common Lisp reader macros for feature test are now supported.  This
feature is present for evaluation purposes and is subject to change.

** `values' now has a setf method

** The `eval-after-load' and `eval-next-after-load' functions are
now available.

** A bug that prevented `current-display-table' to be correctly set
with `set-specifier' has been fixed.

** The bug in easymenu which prevented multiple menus from being
accessible through button3 has been fixed.

You can now safely use easymenu to define multiple menu entries in a
compatible way, with the added menus accessible via button3 as local
submenus.

** Many bugs in the scrollbar code have been fixed.

** First alpha level support of MS Windows NT is available, courtesy
of David Hobley and Marc Paquette.

** Wnn/egg now has initial support Courtesy of Jareth Hein.

** Some old non-working code has been removed until someone chooses
to work on it.

This includes much of the NeXTStep stuff.  The VMS support is also
likely to be removed in the future.

** Many files have been purged out of the etc/ directory.

If you still need the purged files, look for them in the GNU Emacs
distribution.


* Major Differences Between 19.14 and 20.0
===========================================

XEmacs 20.0 is the first public release to have support for MULE
(Multi-Lingual Emacs).  The --with-mule configuration flag must be
used to enable Mule support.

Many bugs have been fixed.  An effort has been made to eradicate all
XEmacs crashes, although we are not quite done yet.  The overall
quality of XEmacs should be higher than any previous release.  XEmacs
now compiles with nary a warning with some compilers.

-- Multiple character sets can be displayed in a buffer.  The file
   mule-doc/demo in the distribution contains a greeting in many
   different languages.

-- Although the Mule work is for all languages, particular effort has
   been invested in Japanese, with particular focus on Japanese users
   of Sun WorkShop.  Many menubar labels have been translated into
   Japanese.  Martin Buchholz, the maintainer of MULE features within
   XEmacs normally runs XEmacs in a Japanese language environment.
   Some of the other contributors are Japanese, most importantly
   Morioka Tomohiko, author of the TM package, providing MIME support
   for Mail and News.

-- Input for complex Asian languages is supported via XIM, a mechanism
   introduced in X11R5 to allow applications to get localized input
   without knowledge of the language.  The way XIM works is that when
   the locale has a complex character set, such as Japanese, and extra
   minibuffer-like status window appears attached to various
   application windows, and indicates the status of the input method.
   Composed input in XEmacs should work the same as with other
   applications.  If Motif and Mule support is configured into XEmacs,
   then XIM support is automatically configured in as well.

-- TM (Tools for Mime) now comes with XEmacs.  This provides MIME
   (Multipurpose Internet Mail Extensions) support for Mail and News.
   The primary author is Morioka Tomohiko.

-- Japanese input can also be input using the `canna' input method.
   This support was contributed by Morioka Tomohiko.  Setting up canna
   usually requires more user effort (and better knowledge of Japanese!)
   than XIM, but provides a better-integrated input method.

-- A mini-tutorial on using Mule:

   -- Every time data passes between XEmacs and the rest of the
      environment, via file or process input or output, XEmacs must
      convert between its internal multi-character representation and
      the external representation (`coding system').  Many
      difficulties with Mule are related to controlling these coding
      system conversions.

      -- file-coding-system, file-coding-system-for-read,
         overriding-file-coding-system, and file-coding-system-alist
         are used to determine the coding systems used on file input
         and output.

      -- For each process, (set-process-input-coding-system) and
         (set-process-output-coding-system) determine the coding
         system used for I/O from the process.

      -- Many other things are encoded using pathname-coding-system:
         -- file and directory names
         -- window manager properties: window title, icon name
         -- process names and process arguments
         -- XIM input.

      -- In many cases, you will want to have the same values for all
         the above variables in many cases.  For example, in a
         Japanese environment, you will want to use the 'euc-japan
         coding system consistently, except when running certain
         processes that do byte-oriented, rather than
         character-oriented I/O, such as gzip, or when processing Mail
         or News, where ISO2022-based coding systems are the norm,
         since they support multiple character sets.

   -- To add support for a new language or character set, start by
      trying to copy code in japanese-hooks.el.

   -- The traditional pre-Mule data conversion is equivalent to the
      'binary coding system under Mule.  In this case all characters
      are treated as iso8859-1 (i.e. characters for English + Western
      European languages).

   -- many fileio-related commands such as find-file and write-file
      take an extra argument, coding-system, which specifies the
      encoding to be used with the file on disk.  For example, here is
      a command that converts from the Japanese EUC to ISO2022 format:

         xemacs -batch -eval '(progn (find-file
         "locale-start.el.euc" (quote euc-japan)) (write-file
         "locale-start.el" nil (quote iso-2022-8-unix)))'

      Interactively, you can be prompted for a coding system by
      providing a prefix argument to the fileio command.  In
      particular, C-u C-x C-f is a useful sequence to edit a file
      using a particular coding system.

   -- In an Asian locale (i.e. if $LANG is set to ja, ko, or zh),
      XEmacs automatically sets up a language environment assuming
      that the operating system encodes information in the national
      version of EUC, which supports English and the national
      language, but typically no other character sets.

-- Command line processing should work much better now - no more order
   dependencies.

-- Many many package upgraded (thanks go to countless maintainers):

  -- ediff 2.64 (Michael Kifer)
  -- Gnus 5.2.40 (Lars Magne Ingebrigtsen)
  -- w3 3.0.51  (Bill Perry)
  -- ilisp 5.8 (Chris McConnell, Ivan Vasquez, Marco Antoniotti, Rick
     Campbell)
  -- VM 5.97     (Kyle Jones)
  -- etags 11.78 (Francesco Potorti`)
  -- ksh-mode.el 2.9
  -- vhdl-mode.el 2.73 (Rod Whitby)
  -- id-select.el (Bob Weiner)
  -- EDT/TPU emulation modes should work now for the first time.
  -- viper 2.92 (Michael Kifer) is now the `official' vi emulator for XEmacs.
  -- big-menubar should work much better now.
  -- mode-motion+.el 3.16
  -- backup-dir 2.0 (Greg Klanderman)
  -- ps-print.el-3.05 (Jacques Duthen Prestataire)
  -- lazy-lock-1.15 (Simon Marshall)
  -- reporter 3.3 (Barry Warsaw)
  -- hm--html-menus 5.0 (Heiko Muenkel)
  -- cc-mode 4.322 (Barry Warsaw)
  -- elp 2.37 (Barry Warsaw)


-- Many new packages have been added:
  -- m4-mode 1.8 (Andrew Csillag)
  -- crisp.el - crisp/brief emulation (Gary D. Foster)
  -- Johan Vroman's iso-acc.el has been ported to XEmacs by Alexandre Oliva
  -- psgml-1.01 (Lennart Staflin, James Clark)
  -- python-mode.el 2.83 (Barry Warsaw)
  -- vrml-mode.el (Ben Wing)
  -- enriched.el, face-menu.el (Boris Goldowsky, Michael Sperber)
  -- sh-script.el (Daniel Pfeiffer)
  -- decipher.el (Christopher J. Madsen)

-- New function x-keysym-on-keyboard-p helps determine keyboard
   characteristics for key rebinding:

  x-keysym-on-keyboard-p: (KEYSYM &optional DEVICE)
    -- a built-in function.
  Return true if KEYSYM names a key on the keyboard of DEVICE.
  More precisely, return true if pressing a physical key
  on the keyboard of DEVICE without any modifier keys generates KEYSYM.
  Valid keysyms are listed in the files /usr/include/X11/keysymdef.h and in
  /usr/lib/X11/XKeysymDB, or whatever the equivalents are on your system.

-- Installed info files are now compressed (support courtesy of Joseph J Nuspl)

-- (load-average) works on Solaris, even if you're not root. Thanks to
   Hrvoje Niksic.

-- OffiX drag-and-drop support added

-- lots of syncing with 19.34 elisp files, most by Steven Baur


** Major Differences Between 19.13 and 19.14
============================================

XEmacs has a new address!  The canonical ftp site is now
ftp.xemacs.org:/pub/xemacs and the Web page is now at
http://www.xemacs.org/.  All mailing lists now have @xemacs.org
addresses.  For the time being the @cs.uiuc.edu addresses will
continue to function.

This is a major new release.  Many features have been added, as well
as many bugs fixed.  The Motif menubar has still _NOT_ been fixed for
19.14.  You should use the Lucid menubar instead.



Major user-visible changes:
---------------------------

-- Color support in TTY mode is provided.  You have to have a TTY capable
   of displaying them, such as color xterm or the console under Linux.
   If your terminal type supports colors (e.g. `xterm-color'), XEmacs
   will automatically notice this and start using color.

-- blink-cursor-mode enables a blinking text cursor.  There is a
   menubar option for this also.

-- auto-show-mode is turned on by default; this means that XEmacs
   will automatically scroll a window horizontally as necessary to
   keep point in view.

-- a file dialog box is provided and will be used whenever you
   are prompted for a filename as a result of a menubar selection.

-- XEmacs can be compiled with built-in GIF, JPEG, and PNG support.
   The GIF libraries are supplied with XEmacs; for JPEG and PNG,
   you have to obtain the appropriate libraries (this is well-
   documented).  This makes image display much easier and faster under
   W3 (the web browser) and TM (adds MIME support to VM and GNUS;
   not yet included with XEmacs but will be in 19.15).

-- XEmacs provides a really nice mode (PSGML with "Wing improvements")
   for editing HTML and other SGML documents.  It parses the document,
   and as a result it does proper indentation, can show you the context
   you're in, the allowed tags at a particular position, etc.

-- XEmacs comes standard with modes for editing Java and VRML code,
   including font-lock support.

-- GNUS 5.2 comes standard with XEmacs.

-- You can now embed colors in the modeline, with different sections
   of the modeline responding appropriately to various mouse gestures:
   For example, clicking on the "read-only" indicator toggles the
   read-only status of a buffer, and clicking on the buffer name
   cycles to the next buffer.  Pressing button3 on these areas brings
   up a popup menu of appropriate commands.

-- There is a much nicer mode for completion lists and such.
   At the minibuffer prompt, if you hit page-up or Meta-V, the completion
   buffer will be displayed (if it wasn't already), you're moved into
   it, and can move around and select filenames using the arrow keys
   and the return key.  Rather than a cursor, a filename is highlighted,
   and the arrow keys change which filename is highlighted.

-- The edit-faces subsystem has also been much improved, in somewhat
   similar ways to the completion list improvements.

-- Many improvements were made to the multi-device support.
   We now provide an auxiliary utility called "gnuattach" that
   lets you connect to an existing XEmacs process and display
   a TTY frame on the current TTY connection, and commands
   `make-frame-on-display' (with a corresponding menubar entry)
   and `make-frame-on-tty' for more easily creating frames on
   new TTY or X connections.

-- We have incorporated nearly all of the functionality of GNU Emacs
   19.30 into XEmacs.  This includes support for lazy-loaded
   byte code and documentation strings, improved paragraph filling,
   better support for margins within documents, v19 regular expression
   routines (including caching of compiled regexps), etc.

-- In accordance with GNU Emacs 19.30, the following key binding
   changes have been made:

   C-x ESC -> C-x ESC ESC
   ESC ESC -> ESC :
   ESC ESC ESC is "abort anything" (keyboard-escape-quit).

-- All major packages have been updated to their latest-released
   versions.

-- XEmacs now gracefully handles a full colormap (such as typically
   results when running Netscape).  The nearest available color
   is automatically substituted.

-- Many bug fixes to the subprocess/PTY code, ps-print, menubar
   functions, `set-text-properties', DEC Alpha support, toolbar
   resizing (the "phantom VM toolbar" bug), and lots and lots
   of other things were made.

-- The ncurses library (a replacement for curses, found especially
   under Linux) is supported, and will be automatically used
   if it can be found.

-- You can now undo in the minibuffer.

-- Surrogate minibuffers now work.  These are also sometimes referred
   to as "global" minibuffers.

-- font-lock has been merged with GNU Emacs 19.30, improved defaults
   have been added, and changes have been made to the way it is
   configured.

-- Many, many modes have menubar entries for them.

-- `recover-session' lets you recover whatever files can be recovered
   after your XEmacs process has died unexpectedly.

-- C-h k followed by a toolbar button press correctly reports
   the binding of the toolbar button.

-- `function-key-map', `key-translation-map', and `keyboard-translate-table'
   are now correctly implemented.

-- `show-message-log' (and its menubar entry under Edit) have been
   removed; instead use `view-lossage' (and its menubar entry under
   Help).

-- There is a standard menubar entry for specifying which browser
   (Netscape, W3, Mosaic, etc.) to use when dispatching URL's
   in mail, Usenet news, etc.

-- Improved native sound support under Linux.

-- Lots of other things we forgot to mention.



Significant Lisp-level changes:
-------------------------------

-- Many improvements to the E-Lisp documentation have been made;
   it should now be up-to-date and complete in nearly all cases.

-- XEmacs has extensive documentation on its internals, for
   would-be C hackers.

-- Common-Lisp support (the CL package) is now dumped standard
   into XEmacs.  No more need for (require 'cl) or anything
   like that.

-- Full support for extents and text properties over strings is
   provided.

-- The extent properties `start-open', `end-open', `start-closed',
   and `end-closed' now work correctly w.r.t. text properties.

-- The `face' property of extents and text properties can now
   be a list.

-- The `mouse-face' property from GNU Emacs is now supported.
   It supersedes the `highlight' property.

-- `enriched' and `facemenu' packages from GNU Emacs have been ported.

-- New functions for easier creation of dialog boxes:
   `get-dialog-box-response', `message-box', and `message-or-box'.

-- `function-min-args' and `function-max-args' allow you to determine
   the minimum and maximum allowed arguments for any type of
   function (i.e. subr, lambda expression, byte-compiled function, etc.).

-- Some C-level support for doing E-Lisp profiling is provided.
   See `start-profiling', `stop-profiling', and
   `pretty-print-profiling-info'.

-- `current-process-time' reports the user, system, and real times
   for the currently running XEmacs process.

-- `next-window', `previous-window', `next-frame', `previous-frame',
   `other-window', `get-lru-window', etc. have an extra device
   argument that allows you to restrict which devices it includes
   (normally all devices).  Some functions that incorrectly ignored
   frames on different devices (e.g. C-x 0) are fixed.

-- new functions `run-hook-with-args-until-success',
   `run-hook-with-args-until-failure'.

-- generalized facility for local vs. global hooks.  See `make-local-hook',
   `add-hook'.

-- New functions for querying the window tree: `frame-leftmost-window',
   `frame-rightmost-window', `window-first-hchild', `window-first-vchild',
   `window-next-child', `window-previous-child', and `window-parent'.

-- Epoch support works.  This gets you direct access to some X events
   and objects (e.g. properties and property-notify events).

-- The multi-device support has been majorly revamped.  There is now
   a new concept of "consoles" (devices grouped together under a
   common keyboard/mouse), console-local variables, and a generalized
   concept of device/console connection.

-- `display-buffer' synched with GNU Emacs 19.30, giving you lots of
   wondrous cruft such as
     -- unsplittable frames
     -- pop-up-frames, pop-up-frame-function
     -- special-display-buffer-names, special-display-regexps,
        special-display-function
     -- same-window-buffer-names, same-window-regexps

-- XEmacs has support for accessing DBM- and/or DB-format databases,
   provided that you have the appropriate libraries on your system.

-- There is a new font style: "strikethru" fonts.

-- New data type "weak list", which is a list with special
   garbage-collection properties, similar to weak hash tables.

-- `set-face-parent' makes one face inherit all properties from another.

-- The junky frame parameters mechanism has been revamped as
   frame properties, which a standard property-list interface.

-- Lots and lots of functions for working with property lists have
   been added.

-- New functions `push-window-configuration', `pop-window-configuration',
   `unpop-window-configuration' for maintain a stack of window
   configurations.

-- Many fixups to the glyph code; icons and mouse pointers are now
   properly merged into the glyph mechanism.

-- `set-specifier' works more sensibly, like `set-face-property'.

-- Many new specifiers for individually controlling toolbar height/width
   and visibility and text cursor visibility.

-- New face `text-cursor' controls the colors of the text cursor.

-- Many new variables for turning on debug information about the
   inner workings of XEmacs.

-- Hash tables can now compare their keys using `equal' or `eql'
   as well as `eq'.

-- Other things too numerous to mention.



Significant configuration/build changes:
----------------------------------------

-- You can disable TTY support, toolbar support, scrollbar support,
   menubar support, and/or dialog box support at configure time
   to save memory.

-- New configure option `--extra-verbose' shows the diagnostic
   output from feature testing; this should help track down
   problems with incorrect feature detection.

-- `dont-have-xmu' is now `with-xmu', with the reversed sense.
   (It defaults to `yes'.)

-- `with-mocklisp' lets you add Mocklisp support if you really
   need this.

-- `with-term' for adding TERM support for Linux users.



** Major Differences Between 19.12 and 19.13
============================================

This is primarily a bug-fix release.  Lots of bugs have been fixed.
Hopefully only a few have been introduced.  The most noteworthy bug
fixes are:

 -- There should be no more problems connecting XEmacs to an X
    server over SLIP or other slow connections.
 -- Periodic crashes when using the Buffers menu should be gone.
 -- etags would sometimes erase the current buffer; it doesn't
    any more.
 -- XEmacs will correctly exit if the X server dies.
 -- uniconified frames are displayed properly under TVTWM.
 -- Breakage in `add-menu-item' / `add-menu-button' is fixed.

The Motif menubar has _NOT_ been fixed for 19.13.  You should use the
Lucid menubar instead.

Multi-device support should now be working properly.  You can now open
an X device after having started out on a TTY device.

Background pixmaps now work.  See `set-face-background-pixmap'.

Echo area messages are now saved to a buffer, " *Message Log*".  To
see this buffer, use the command `show-message-log'.  It is possible
to filter the message which are actually included by modifying the
variables `log-message-ignore-regexps' and `log-message-ignore-labels'.

You can now control which warnings you want to see.  See
`display-warning-suppressed-classes' and friends.

You can now set the default location of an "other window" from the
Options menu.

"Save Options" now saves the state of all faces.

You can choose which file "Save Options" writes into; see
`save-options-file'.

XPM support is no longer required for the toolbar.

The relocating allocator is now enabled by default whenever possible.
This allows buffer memory to be returned to the system when no longer
in use which helps keep XEmacs process size down.

The ability to have captioned toolbars has been added.  Currently only
the default toolbar actually has a captioned version provided.  A new
specifier variable, `toolbar-buttons-captioned-p' controls whether the
toolbar is captioned.

A copy of the XEmacs FAQ is now included and is available through info.

The on-line E-Lisp reference manual has been significantly updated.

There is now audio support under Linux.

Modifier keys can now be sticky.  This is controlled by the variable
`modifier-keys-are-sticky'.

manual-entry should now work correctly under Irix with the penalty of
a longer startup time the first time it is invoked.  If you are having
problems with this on another system try setting
`Manual-use-subdirectory-list' to t.

make-tty-device no longer automatically creates the first frame.

Rectangular regions now work correctly.

ediff no longer sets synchronize-minibuffers to t unless you first set
ediff-synchronize-minibuffers

keyboard-translate-table has been implemented.  This means that the
`enable-flow-control' command for dealing with TTY connections that
filter out ^S and ^Q now works.

You can now create frames that are initially unmapped and frames that
are "transient for another frame", meaning that they behave more like
dialog-box frames.

Other E-Lisp changes:

-- Specifier `menubar-visible-p' for controlling menubar visibility
-- Local command hooks should be set using `local-pre-command-hook'
   and `local-post-command-hook' instead of making the global
   equivalents be buffer-local.
-- `quit-char', `help-char', `meta-prefix-char' can be any key specifier
   instead of just an integer.
-- new functions `add-async-timeout' and `disable-async-timeout'.
   These let you create asynchronous timeouts, which are like
   normal timeouts except that they're executed even during
   running Lisp code.  Use this with care!
-- `debug-on-error' and `stack-trace-on-error' now enter the debugger
   only when an *unhandled* error occurs.  If you want the old
   behavior, use `debug-on-signal' and `stack-trace-on-signal'.
-- \U, \L, \u, \l, \E recognized specially in `replace-match'.
   These are standard ex/perl commands for changing the case of
   replaced text.
-- New function event-matches-key-specifier-p.  This provides
   a clean way of comparing keypress events with key specifiers
   such as 65, (shift home), etc. without having to resort
   to ugly `character-to-event' / `event-to-character' hacks.
-- New function `add-to-list'
-- New Common-Lisp functions `some', `every', `notevery', `notany',
   `adjoin', `union', `intersection', `set-difference',
   `set-exclusive-or', `subsetp'
-- `remove-face-property' provides a clean way of removing a
   face property.

Many of the Emacs Lisp packages have been updated.  Some of the new
Emacs Lisp packages ---

ada-mode:  major mode for editing Ada source

arc-mode:  simple editing of archives

auto-show-mode:  automatically scrolls horizontally to keep point on-screen 

completion:  dynamic word completion mode

dabbrev:  the dynamic abbrev package has been rewritten and is much
          more powerful -- e.g. it searches in other buffers as well
          as the current one

easymenu:  menu support package

live-icon:  makes frame icons represent the current frame contents

mailcrypt 3.2:  mail encryption with PGP; included but v2.4 is still
		the default

two-column:  for editing two-column text 


** Major Differences Between 19.11 and 19.12
============================================

This is a huge new release.  Almost every aspect of XEmacs has been changed
at least somewhat.  The highlights are:

-- TTY support (includes face support)
-- new redisplay engine; should be faster, less buggy, and more powerful
-- terminology change from "screen" to "frame"
-- built-in toolbar
-- toolbar support added to many packages
-- multiple device support (still in beta; improvements to come in
   19.13)
-- Purify used to ensure that there are no memory leaks or memory corruption
   problems
-- horizontal and vertical scrollbars in all windows
-- new Lucid (i.e. look-alike Motif) scrollbar widget
-- stay-up menus in the Lucid (look-alike Motif) menubar widget
-- 3-d modeline
-- new extents engine; should be faster, less buggy, and more powerful
-- much more powerful control over faces
-- expanded menubar
-- more work on synching with GNU Emacs 19.28
-- new packages: Hyperbole, OOBR (object browser), hm--html-menus, viper,
   lazy-lock.el, ksh-mode.el, rsz-minibuf.el
-- package updates for all major packages
-- dynodump package for Solaris: provides proper undumping and portable
   binaries across different OS versions and machine types
-- Greatly expanded concept of "glyphs" (pixmaps etc. in a buffer)
-- built-in support for displaying X-Faces, if the X-Face library is
   available
-- built-in support for SOCKS if the SOCKS library is available
-- graceful behavior when the colormap is full (e.g. Netscape ate
   all the colors)
-- built-in MD5 (secure hashing function) support


More specific information:

*** TTY Support
---------------

The long-awaited TTY support is now available.  XEmacs will start up
in TTY mode (using the tty you started XEmacs from) if the DISPLAY
environment variable is not set or if you use the `-nw' option.

Faces are available on TTY's.  For a demonstration, try editing a C
file and turning on font-lock-mode.

You can also connect to additional TTY's using `make-tty-device',
whether your first frame was a TTY or an X window.  This ability is
not yet completely finished.

The full event-loop capabilities (processes, timeouts, etc.) are
available on TTY's.



*** New Redisplay Engine
------------------------

The redisplay engine has been rewritten to improve its efficiency and
to increase its functionality.  It should also be significantly more
bug-free than the previous redisplay engine.

A line that is not big enough to display at the bottom of the window
will normally be clipped (so that it is partially visible) rather than
not displayed at all.  The variable `pixel-vertical-clip-threshold'
can be used to control the minimum space that must be available for a
line to be clipped rather than not displayed at all.

Tabs are displayed in such a way that things line up fairly well even
in the presence of variable-width fonts and/or lines with
multiply-sized fonts.

Display tables are implemented, through the specifier variable
`current-display-table'.  They can be buffer-local, window-local,
frame-local, or device-local.  See below for info about specifiers.



*** Toolbar
-----------

There is now built-in support for a toolbar.  A sample toolbar is
visible by default at the top of the frame.  Four separate toolbars
can be configured (at the top, bottom, left, and right of the frame).
The toolbar specification is similar to the menubar specification.
The up, down, and disabled glyphs of a toolbar button can be
separately controlled.  Explanatory text can be echoed in the echo
area when the mouse passes over a toolbar button.  The size, contents,
and visibility of the various toolbars can be controlled on a
per-buffer, per-window, per-frame, and per-device basis through the
use of specifiers.  See the chapter on toolbars in the Lisp Reference
Manual (included with XEmacs) for more information.

The toolbar color and shadow thicknesses are currently controlled only
through `modify-frame-parameters' and through X resources.  We are
planning on making these controllable through specifiers as well. (Our
hope is to make `modify-frame-parameters' obsolete, as it is a clunky
and not very powerful mechanism.)

Info, GNUS, VM, W3, and various other packages include custom toolbars
with them.



*** Menubar
-----------

Stay-up menus are implemented in the look-alike Motif menubar.

The default menubar has been expanded to include most commonly-used
functions in XEmacs.

The options menu has been greatly expanded to include many more
options.

The menubar specification format has been greatly expanded.  Per-menu
activation hooks can be specified through the :filter keyword (thus
obsoleting `activate-menubar-hook'); this allows for fast response
time when you have a large and complex menu.  You can dynamically
control whether menu items are present through the :included and
:config keywords. (The latter keyword implements a simple menubar
configuration scheme, in conjunction with the variable
`menubar-configuration'.) Many different menu-item separators (single
or double line; solid or dashed; flat, etched-in, or etched-out) are
available.  See the chapter on menus in the Lisp Reference Manual for
more information about all of this.

New functions `add-submenu' and `add-menu-button' are available.
These supersede the older `add-menu' and `add-menu-item' functions,
and provide a more powerful and consistent interface.

New convenience functions for popping up the part or all of the
menubar in a pop-up menu are available: `popup-menubar-menu' and
`popup-buffer-menu'.

Menus are now incrementally constructed greatly improving menubar
response time.



*** Scrollbars
--------------

A look-alike Motif scrollbar is now included with XEmacs.  No longer
will you have to suffer with ugly Athena scrollbars.

Windows can now have horizontal scrollbars.  Normally they are visible
when the window's buffer is set to truncate lines rather than wrap
them (e.g. `(setq truncate-lines t)').

All windows, not only the right-most ones, can have vertical
scrollbars.

The functions to change a scrollbar's width have been superseded by
the specifier variables `scrollbar-width' and `scrollbar-height'.
This allows their values to be controlled on a buffer-local,
window-local, frame-local, and device-local basis.  See below.

The scrollbars interact better with the event loop (for example, you
can type `C-h k', do a scrollbar action, and see a description of this
scrollbar action printed as if you had pressed a key sequence or
selected a menu item).

The scrollbar behavior can be reprogrammed, by advising the
`scrollbar-*' functions.



*** Key Bindings
----------------

The oft-used function `goto-line' now has its own binding: M-g.

New bindings are available for scrolling the "other" window: M-next,
M-prior, M-home, M-end. (On many keyboards, `next' and `prior'
labelled `PgUp' and `PgDn'.)

You can reactivate a deactivated Zmacs region, without having any
other effects, with the binding M-C-z.

The bindings `M-u', `M-l', and `M-c' now work on the region (if a
region is active) or work on a word, as before.

Shift-Control-G forces a "critical quit", which drops immediately into
the debugger; see below.



*** Modeline
------------

The modeline can now have a 3-d look; this is enabled by default.  The
specifier variable `modeline-shadow-thickness' controls the size.

The modeline can now be turned off on a per-buffer, per-window,
per-frame, or per-device basis.  The specifier variable
`has-modeline-p' controls whether the modeline is visible.  See below
for details about the vastly powerful specifier mechanism.

The modeline functions and variables have been renamed to be
`*-modeline-*' rather than `*-mode-line-*'.  Aliases are provided for
all the old names.

Variable width fonts now work correctly when used in the modeline.



*** Minibuffer, Echo Area
-------------------------

The minibuffer is no longer constrained to be one line high.  The
package rsz-minibuf.el is included to automatically resize the
minibuffer when its contents are too big; enable this with
`resize-minibuffer-mode'.

The echo area is now a true buffer, called " *Echo Area*".  This
allows you to customize the echo area behavior through
before-change-functions and after-change-functions.



*** Specifiers
--------------

XEmacs has a new concept called "specifiers", used to configure most
display options (toolbar size and contents, scrollbar size, face
properties, modeline visibility and shadow-thickness, glyphs, display
tables, etc.).  We are planning on converting all display
characteristics to use specifiers, and obsoleting the clunky functions
`frame-parameters' and `modify-frame-parameters'.  Specifically:

-- You can specify values (called "instantiators") for particular
   "locales" (i.e. buffers, windows, frames, devices, or a global value).
   When determining what the actual value (or "instance") of a specifier
   is, the specifications that are provided are searched from most
   specific (i.e. buffer-local) to most general (i.e. global), looking
   for a matching one.

-- You can specify multiple instantiators for a particular locale.
   For example, when specifying what the foreground color of a face
   is in a particular buffer, you could specify two instantiators:
   "dark sea green" and "green".  The color would then be dark sea
   green on devices that recognize that color, and green on other
   devices.  You have effectively provided a fallback value to make
   sure you get reasonable behavior on all devices.

-- You can add one or more tags to an instantiator, where a tag
   is a symbol that has been previously registered with XEmacs.
   This allows you to identify your instantiators for later
   removal in a way that won't interfere with other applications
   using the same specifier.  Furthermore, particular tags can
   be restricted to match only particular sorts of devices.
   Any tagged instantiator will be ignored if the device over which
   it is being instanced does not match any of its tags.  This
   allows you, for example, to restrict an instantiator to a
   particular device type (X or TTY) and/or class (color, grayscale,
   or mono). (You might want to specify, for example, that a
   particular face is displayed in green on color devices and is
   underlined on mono devices.)

-- A full API is provided for manipulating specifiers, and full
   documentation is provided in the Lisp Reference Manual.



*** Basic Lisp Stuff
--------------------

Common-Lisp backquote syntax is recognized.  For example, the old
expression

(` (a b (, c)))

can now be written

`(a b ,c)

The old backquote syntax is still accepted.

The new function `type-of' returns a symbol describing the type of a
Lisp object (`integer', `string', `symbol', etc.)

Symbols beginning with a colon (called "keywords") are treated
specially in that they are automatically made self-evaluating when
they are interned into `obarray'.  The new function `keywordp' returns
whether a symbol begins with a colon.

`get', `put', and `remprop' have been generalized to allow you to set
and retrieve properties on many different kinds of objects: symbols,
strings, faces, glyphs, and extents (for extents, however, this is not
yet implemented).  They are joined by a new function `object-props'
that returns all of the properties that have been set on an object.

New functions `plists-eq' and `plists-equal' are provided for
comparing property lists (a property list is an alternating list
of keys and values).

The Common-Lisp functions `caar', `cadr', `cdar', `cddr', `caaar', etc.
(up to four a's and/or d's), `first', `second', `third', etc. (up to
`tenth'), `last', `rest', and `endp' have been added, for more
convenient manipulation of lists.

New function `mapvector' maps over a sequence and returns a vector
of the results, analogous to `mapcar'.

New functions `rassoc', `remassoc', `remassq', `remrassoc', and
`remrassq' are provided for working with alists.

New functions `defvaralias', `variable-alias' and `indirect-variable'
are provided for creating variable aliases.

Strings have a modified-tick that is bumped every time a string
is modified in-place with `aset' or `fillarray'.  This is retrieved
with the new function `string-modified-tick'.

New macro `push' destructively adds an element to the beginning of a
list.  New macro `pop' destructively removes and returns the first
element of a list.



*** Buffers
-----------

Most functions that operate on buffer text now take an optional BUFFER
argument, specifying which buffer they operate on.  (Previously, they
always operated on the current buffer.)

The new function `transpose-regions' is provided, ported from GNU
Emacs.

The new function `save-current-buffer' works like `save-excursion'
but only saves the current buffer, not the location of point in
that buffer.



*** Devices
-----------

XEmacs has a new concept of "device", which is represents a particular
X display or TTY connection.  `make-frame' has a new, optional device
parameter that allows you to specify which device the frame is to be
created on.

Multiple simultaneous TTY and/or X connections may be made.  The
specifier mechanism provides reasonable behavior of glyphs, faces,
etc. over heterogeneous device types and over devices whose individual
capabilities may vary.

There is also a device type called "stream" that represents a STDIO
device that has no redisplay or cursor-motion capabilities, such as
the "glass terminal" that XEmacs uses when it is run noninteractively.
There is not all that much you can do with stream devices currently;
please let us know if there are good uses you can think of for this
capability. (For example, log files?)

A new device API is provided.  Functions are provided such as
`device-name' (the name of the device, which generally is based on the
X display or TTY file name), `device-type' (X, TTY, or stream),
`device-class' (color, grayscale, or mono), etc.  See the Lisp
Reference Manual.

Many functions have been extended to contain an additional, optional
device argument, where such an extension makes sense.  In general, if
the argument is omitted, it is equivalent to specifying
`(selected-device)'.

Many previous functions and variables are obsoleted in favor of the
device API.  For example, `window-system' is obsoleted by
`device-type', and `x-color-display-p' and friends are obsoleted by
`device-class'.

** NOTE **: The obsolete variable `window-system' is going
to be deleted soon, probably in 19.14.  Please correct all
your code to use `device-type'.

** INCOMPATIBLE CHANGE **: The function `x-display-visual-class'
returns different values from previous versions of XEmacs.



*** Errors, Warnings, C-g
-------------------------

There is a new warnings system implemented.  Many warnings that were
formerly displayed in various ad-hoc ways (e.g. warnings about screwy
modifier mappings, messages about failures handling the mouse cursor
and errors in a gc-hook) have been regularized through this system.
The new function `warn' displays a warning before the next redisplay
(the actually display of the warning messages is accomplished through
`display-warning-buffer').  Both `warn' and `display-warning-buffer'
are Lisp functions (the C code calls out to them as necessary), and
thus you can customize the warning system.

Under an X display, you can press Shift-Control-G to force a "critical
quit".  This will immediately display a backtrace and pop you into the
debugger, regardless of the settings of `inhibit-quit' and
`debug-on-quit'.

C-g now works properly even on systems that don't implement SIGIO or
for which SIGIO is broken (e.g. IRIX 5.3 and older versions of Linux).
In addition, the SIGIO support has been fixed for many systems on
which it didn't always work properly before (e.g. HPUX and Solaris).

   

*** Events
----------

** INCOMPATIBLE CHANGE **: Many event functions have been changed to
accept and return windows instead of frames.

New function: `event-live-p', specifying whether `deallocate-event'
has been called on an event.

The "menu event" type has been renamed to "misc-user event", and
encompasses scrollbar events as well as menu events.  We are planning
on making it also encompass toolbar events in a future release.

New functions are provided for determining whether an particular
sections of a frame: `event-over-border-p', `event-over-glyph-p',
`event-over-modeline-p', `event-over-text-area-p', and
`event-over-toolbar-p'.  The old, kludgey methods of checking the
window-height, the internal-border-width, etc. are unreliable and
should not be used.

New functions `event-window-x-pixel' and `event-window-y-pixel' are
provided for determining where in a particular window an event
happened.

New functions `event-glyph-x-pixel' and `event-glyph-y-pixel' are
provided for determining where in a particular glyph an event
happened.

New function `event-closest-point', which returns the closest buffer
position to the event even if the event did not occur over any text.

New variable `unread-command-events', superseding the older
`unread-command-event'.

Many event-loop bugs have been fixed.



*** Extents
-----------

The extent code has been largely rewritten.  It should be faster and
more reliable.

The text-property implementation has been greatly improved.

Some new extent primitives are provided to return the position of the
next or previous property change in a buffer.

Extents can now have a parent specified; then all of its properties
(except for the buffer it's in and its position in that buffer) come
from that extent.  Hierarchies of such extents can be created.

Extents now have a `detachable' property that controls what happens
(they either get detached or shrink down to zero-length) when their
text is deleted.  Previously, such extents would always be detached.

The `invisible' property on extents now works.

`map-extents' has three additional parameters that provide more
control over which extents are mapped.

`map-extents' deals better with changes made to extents in the
buffer being mapped over.

A new function `mapcar-extents' (an alternative to `map-extents') has
been provided and should be easier to use than `map-extents'.



*** Faces
---------

Faces can now be buffer-local, window-local, and device-local as well
as frame-local, and can be further restricted to a particular device
type or class.  The way in which faces can be controlled is now based
on the general and powerful specifier mechanism; see above.

The new function `set-face-property' generalizes `set-face-font',
`set-face-foreground', etc. and takes many new optional arguments, in
accordance with the new specifier mechanism.

The new functions `face-property' and `face-property-instance'
generalize `face-font', `face-foreground', etc. and take many new
optional arguments, in accordance with the new specifier mechanism.
(`face-property' returns the value, if any, that was specified for a
particular locale, and `face-property-instance' returns the actual
value that will be used for display.  See the section on specifiers.)

The functions `face-font', `face-foreground', `face-background',
`set-face-font', `set-face-foreground', `set-face-background',
etc. are now convenience functions, trivially implemented using
`face-property' and `set-face-property' and take new optional
arguments in accordance with those functions.  New convenience
functions `face-font-instance', `face-foreground-instance',
`face-background-instance', etc. are provided and are trivially
implemented using `face-property-instance'.

Inheritance of face properties can now be specified.  Each individual
face property can inherit differently from other properties, or not
inherit at all.

You can set user-defined properties on faces using
`set-face-property'.

You can create "temporary" faces, which are faces that disappear
when they are no longer in use.  This is as opposed to normal
faces, which stay around forever.

The function `make-face' takes a new optional argument specifying
whether a face should be permanent or temporary, and returns the
actual face object rather than the face symbol, as in previous
versions of XEmacs.

The function `face-list' takes a new optional argument specifying
whether permanent, temporary, or both kinds of faces should be
returned.

Faces have new TTY-specific properties: `highlight', `reverse',
`alternate', `blinking', and `dim'.

Redisplay is smarter about dealing with face changes: changes to a
particular face no longer cause all frames to be cleared and
redisplayed.

The Edit-Faces package is provided for interactively changing faces.
A menu item on the options menu is provided for this.

New functions are provided for retrieving the ascent, descent, height,
and width of a character in a particular face.



*** Fonts, Colors
-----------------

** INCOMPATIBLE CHANGE **: The old "font" and "pixel" objects are gone.
In place are new objects "font specifier", "font instance", "color
specifier", and "color instance".  Functions `font-name', `pixel-name'
(an obsolete alias for `color-name'), etc. are now convenience
functions for working with font and color specifiers.  Old code that
is not too sophisticated about working with font and pixel objects may
still work, though.  (For example, the idiom `(font-name (face-font
'default))' still works.)

You can now extract the RGB components of a color-instance object
(similar to the old pixel object) with the function
`color-instance-rgb-components'.  There is also a convenience function
`color-rgb-components' for working with color specifiers.

If there are no more colors available in the colormap, the nearest
existing color will be used when allocating a new color.



*** Frames
----------

What used to be called "screens" are now called "frames", for clarity
and consistency with GNU Emacs.  Aliases are provided for all the old
screen functions and variables, to avoid introducing a huge E-Lisp
incompatibility.

The frame code has been merged with GNU Emacs 19.28, providing
improved functionality for many functions.



*** Glyphs, Images, and Pixmaps
-------------------------------

Glyphs (used in various places, i.e. as begin-glyphs and end-glyphs
attached to extents and appearing in a buffer or in marginal
annotations; as the truncator and continuor glyphs marking line wrap
or truncation; as an overlay at the beginning of a line; as the
displayable element in a toolbar button; etc.) can now be
buffer-local, window-local, frame-local, and device-local, and can be
further restricted to a particular device type or class.  The way in
which faces can be controlled is now based on the general and powerful
specifier mechanism; see above.

** INCOMPATIBLE CHANGE **: The glyph and pixmap API has been completely
overhauled.  A new Lisp object "glyph" is provided and should be used
where the old "pixmap" object would have been used.  The pixmap object
exists no longer.  There are also new Lisp objects "image specifier"
and "image instance" (an image-instance is the closest equivalent to
what a pixmap object was).  More work on glyphs and images is slated
for 19.13.  The glyph and image docs in the Lisp Reference Manual are
incomplete and will be finished in 19.13.

The new function `set-glyph-property' allows setting of all the
glyph properties (`baseline', `contrib-p', etc.).  Convenience
functions for particular properties are also provided, just like
for faces.

You can set user-defined properties on glyphs using the new function
`set-glyph-property'.

When displaying pixmaps, existing, closest-matching colors will be
used if the colormap is full.

If the compface library is compiled into XEmacs, there is built-in
support for displaying X-Face bitmaps. (These are typically small
pictures of people's faces, included in a mail message through the
X-Face: header.) VM and highlight-headers will automatically use the
built-in X-Face support if it is available.

Annotations in the right margin (as well as the left margin) are now
implemented.  The left and right margin width functions have been
superseded by the specifier variables `left-margin-width' and
`right-margin-width', allowing much more flexible control through the
specifier mechanism.

** INCOMPATIBLE CHANGE **: The variable `use-left-overflow',
for controlling annotations in the left margin, is now a specifier
variable instead of a buffer-local variable.  (There is also a new
variable `use-right-overflow', that is complementary.)



*** Hashing
-----------

Two new types of weak hashtables can be created: key-weak and
value-weak.  In a key-weak hashtable, an entry remains around
if its key is referenced elsewhere, regardless of whether this
is also the case for the value.  Value-weak hashtables are
complementary. (This is as opposed to the traditional weak
hashtables, where an entry remains around only if both the
key and value are referenced elsewhere.) New functions
`make-key-weak-hashtable' and `make-value-weak-hashtable'
are provided for creating these hashtables.

The new function `md5' is provided for performing an MD5
hash of an object.  MD5 is a secure message digest algorithm
developed by RSA, inc.



*** Keymaps
-----------

The GNU Emacs concept of `function-key-map' is now partially
implemented.  This allows conversion of function-key escape sequences
such as `ESC [ 1 1 ~' into an equivalent human-readable keysym such as
`F1'.  This work will be completed in 19.14.  The function-key map is
device-local and controllable through the functions
`device-function-key-map' and `set-device-function-key-map'.

`where-is-internal' now correctly searches minor-mode keymaps,
extent-local keymaps, etc.  As a side effect of this, menu items will
now correctly show the keyboard equivalent for commands that are
available through a minor-mode keymap, extent-local keymap, etc.

** INCOMPATIBLE CHANGE **: The modifier key "Symbol" has
been renamed to "Alt", for compatibility with the rest of the world.
Keep in mind that on many keyboards, the key labelled "Alt" actually
generates the "Meta" modifier.  (On Sun keyboards, however, the key
labelled "Alt" does indeed generate the "Alt" modifier, and the key
labelled with a diamond generates the "Meta" modifier.)



*** Mouse, Active Region
------------------------

The mouse internals in mouse.el have been rewritten.  Hooks have been
provided for easier customization of mouse behavior.  For example, you
can now easily specify an action to be invoked on single-click
(i.e. down-up without appreciable motion), double-click, drag-up, etc.

Some code from GNU Emacs has been ported over, generalizing some of
the X-specific mouse stuff.

** INCOMPATIBLE CHANGE **: The function `set-mouse-position' accepts
a window instead of a frame.

New function `mouse-position' that obsoletes and is more powerful than
`read-mouse-position'.

New functions `mouse-pixel-position' and `set-mouse-pixel-position' for
working with pixels instead of characters.

The active (Zmacs) region is now highlighted using the `zmacs-region-face'
instead of the `primary-selection-face'; this generalizes what used
to be X-specific.

New functions `region-active-p', `region-exists-p', and `activate-region'
provide a uniform API for dealing with the region irrespective of
whether the variable `zmacs-regions' is set.

XEmacs is now a better X citizen with respect to the primary selection:
it does not stomp on the primary selection quite so much.  This makes
things more manageable if you set `zmacs-regions' to nil.



*** Processes
-------------

Various process race conditions and bugs have been fixed.  Problems
with process termination not getting noticed until much later (if at
all) should be gone now, as well as problems with zombie processes
under some systems.

SOCKS support is now included.  SOCKS is a package that allows hosts
behind a firewall to gain full access to the Internet without
requiring direct IP reachability.



*** Windows
-----------

Windows 95 is still not out yet.

** INCOMPATIBLE CHANGE **: The functions `locate-window-from-coordinates'
and `window-edges' have been eliminated.  It no longer makes sense to
work with windows in terms of character positions, because windows can
(and often do) have many differently-sized fonts in them, because the
3-D modeline is not exactly one line high, etc.

The new functions `window-pixel-edges', `window-highest-p',
`window-lowest-p', `frame-highest-window', and `frame-lowest-window'
are provided as substitutes for the above-mentioned, deleted
functions.

The function `window-end' now takes an optional GUARANTEE argument
that will ensure that the value is actually correct as of the next
redisplay.

The window code has been merged with GNU Emacs 19.28, providing
improved functionality for many functions.



*** System-Specific Information
-------------------------------

Georg Nikodym's dynodump package is provided, for proper unexec()ing
on Solaris systems.  Executables built on Solaris 2.3 can now run on
Solaris 2.4 without crashing; similarly with executables built on one
type of Sun machine and run on another.

AIX 4.x is supported.

The NeXTstep operating system is supported in TTY mode (this is still
in beta).  There are plans to port XEmacs to the NeXTstep window
system, but it may be awhile before this is complete.

Problems with the `round' function causing arithmetic errors on HPUX 9
have been fixed.

You can now build XEmacs as an ELF executable on Linux systems that
support ELF.

Various other new system configurations are supported.



*** Packages
------------

Most packages have been updated to the latest available versions.


Some of the new Emacs Lisp packages ---

Hyperbole: the everyday information manager.  Provides a Rolodex,
	   allows links to be embedded in text, etc.

OOBR: a sophisticated class browser for object-oriented languages.

viper: a better VI emulator that allows Emacs and VI features
       to coexist happily.

hm--html-menus: a sophisticated package for editing HTML code,
		from Heiko Muenkel.

ksh-mode.el: for editing shell scripts.

lazy-lock.el: a lazy, on-the-fly fontifier.

paren.el: an improved matching paren highlighter



Major changes to existing packages --

VM: has a toolbar, many other nice features.

w3: has a toolbar, many other nice features.

ediff: provides three-way merging, has a better user interface.

info: has a toolbar.

highlight-headers.el: now highlights URL's and makes them active so
		      that when clicked either Netscape 1.1 is called
		      or Emacs W3 is run.


** Major Differences Between 19.10 and 19.11
============================================
  
The name has changed from "Lucid Emacs" to "XEmacs".  Along with this is a
new canonical ftp site: cs.uiuc.edu:/pub/xemacs.

XEmacs now has its very own World Wide Web page!  It contains a
complete list of the FTP distribution sites, the most recent FAQ,
pointers to Emacs Lisp packages not included with the distribution, and
other useful stuff.  Check it out at http://xemacs.cs.uiuc.edu/.

A preliminary New Users Guide.

cc-mode.el now provides the default C, C++ and Objective-C modes.

The primary goal of this release is stability.  Very few new features have
been introduced but lots of bugs have been fixed.  Many of the Emacs Lisp
packages have been updated.

Some of the new Emacs Lisp packages ---

tcl-mode.el:  major mode for editing TCL code

fast-lock.el: saves and restores font-lock highlighting, greatly
            reducing the time necessary for loading a font-lock'ed
            file

ps-print.el: prints buffers to Postscript printers preserving the
           buffer's bold and italic text attributes

toolbar.el: provides a "fake" toolbar for use with XEmacs (an
          integrated one will be included with 19.12)


** Major Differences Between 19.9 and 19.10
===========================================

The GNU `configure' system is now used to build lemacs.

The Emacs Manual and Emacs Lisp Reference Manual now document version 19.10.
If you notice any errors, please let us know.

When pixmaps are displayed in a buffer, they contribute to the line height -
that is, if the glyph is taller than the rest of the text on the line, the
line will be as tall as necessary to display the glyph.

In addition to using arbitrary sound files as emacs beeps, one can control
the pitch and duration of the standard X beep, on X servers which allow that
(Note: most don't.)

There is support for playing sounds on systems with NetAudio servers.

Minor modes may have mode-specific key bindings; keymaps may have an arbitrary
number of parent maps.

Menus can have toggle and radio buttons in them.

There is a font selection menu.

Some default key bindings have changed to match FSF19; the new bindings are

  Screen-related commands:
        C-x 5 2                 make-screen
        C-x 5 0                 delete-screen
        C-x 5 b                 switch-to-buffer-other-screen
        C-x 5 f                 find-file-other-screen
        C-x 5 C-f               find-file-other-screen
        C-x 5 m                 mail-other-screen
        C-x 5 o                 other-screen
        C-x 5 r                 find-file-read-only-other-screen
  Abbrev-related commands:
        C-x a l                 add-mode-abbrev
        C-x a C-a               add-mode-abbrev
        C-x a g                 add-global-abbrev
        C-x a +                 add-mode-abbrev
        C-x a i g               inverse-add-global-abbrev
        C-x a i l               inverse-add-mode-abbrev
        C-x a -                 inverse-add-global-abbrev
        C-x a e                 expand-abbrev
        C-x a '                 expand-abbrev
  Register-related commands:
        C-x r C-SPC             point-to-register
        C-x r SPC               point-to-register
        C-x r j                 jump-to-register
        C-x r s                 copy-to-register
        C-x r x                 copy-to-register
        C-x r i                 insert-register
        C-x r g                 insert-register
        C-x r r                 copy-rectangle-to-register
        C-x r c                 clear-rectangle
        C-x r k                 kill-rectangle
        C-x r y                 yank-rectangle
        C-x r o                 open-rectangle
        C-x r t                 string-rectangle
        C-x r w                 window-configuration-to-register
  Narrowing-related commands:
        C-x n n                 narrow-to-region
        C-x n w                 widen
  Other changes:
        C-x 3                   split-window-horizontally (was undefined)
        C-x -                   shrink-window-if-larger-than-buffer
        C-x +                   balance-windows

The variable allow-deletion-of-last-visible-screen has been removed, since 
it was widely hated.  You can now always delete the last visible screen if
there are other iconified screens in existence.

ToolTalk support is provided.

An Emacs screen can be placed within an "external client widget" managed
by another application.  This allows an application to use an Emacs screen
as its text pane rather than the standard Text widget that is provided
with Motif or Athena.

Additional compatibility with Epoch is provided (though this is not yet
complete.)


** Major Differences Between 19.8 and 19.9
==========================================

Scrollbars!  If you have Motif, these are real Motif scrollbars; otherwise,
Athena scrollbars are used.  They obey all the usual resources of their
respective toolkits.

There is now an implementation of dialog boxes based on the Athena
widgets, as well as the existing Motif implementation.

This release works with Motif 1.2 as well as 1.1.  If you link with Motif, 
you do not also need to link with Athena.

If you compile lwlib with both USE_MOTIF and USE_LUCID defined (which is the
recommended configuration) then the Lucid menus will draw text using the Motif
string-drawing library, instead of the Xlib one.  The reason for this is that
one can take advantage of the XmString facilities for including non-Latin1
characters in resource specifications.  However, this is a user-visible change
in that, in this configuration, the menubar will use the "*fontList" resource 
in preference to the "*font" resource, if it is set.

It's possible to make extents which are copied/pasted by kill and undo.
There is an implementation of FSF19-style text properties based on this.

There is a new variable, minibuffer-max-depth, which is intended to circumvent
a common source of confusion among new Emacs users.  Since, under a window
system, it's easy to jump out of the minibuffer (by doing M-x, then getting
distracted, and clicking elsewhere) many, many novice users have had the
problem of having multiple minibuffers build up, even to the point of
exhausting the lisp stack.  So the default behavior is to disallow the
minibuffer to ever be reinvoked while active; if you attempt to do so, you
will be prompted about it.

There is a new variable, teach-extended-commands-p, which if set, will cause
`M-x' to remind you of any key bindings of the command you just invoked the
"long way."

There are menus in Dired, Tar, Comint, Compile, and Grep modes.

There is a menu of window management commands on the right mouse button over
the modelines.

Popup menus now have titles at the top; this is controlled by the new 
variable `popup-menu-titles'.

The `Find' key on Sun keyboards will search for the next (or previous)
occurrence of the selected text, as in OpenWindows programs.

The `timer' package has been renamed to `itimer' to avoid a conflict with
a different package called `timer'.

VM 5.40 is included.

W3, the emacs interface to the World Wide Web, is included.

Felix Lee's GNUS speedups have been installed, including his new version of
nntp.el which makes GNUS efficiently utilize the NNTP XOVER command if
available (which is much faster.)  

GNUS should also be much friendlier to new users: it starts up much faster,
and doesn't (necessarily) subscribe you to every single newsgroup.

The byte-compiler issues a new class of warnings: variables which are
bound but not used.  This is merely an advisory, and does not mean the
code is incorrect; you can disable these warnings in the usual way with
the `byte-compiler-options' macro.

the `start-open' and `end-open' extent properties, for specifying whether
characters inserted exactly at a boundary of an extent should go into the
extent or out of it, now work correctly.

The `extent-data' slot has been generalized/replaced with a property list,
so it's easier to attach arbitrary data to extent objects.

The `event-modifiers' and `event-modifier-bits' functions work on motion
events as well as other mouse and keyboard events.

Forms-mode uses fonts and read-only regions.

The behavior of the -geometry command line option should be correct now.

The `iconic' screen parameter works when passed to x-create-screen.

The user's manual now documents Lucid Emacs 19.9.

The relocating buffer allocator is turned on by default; this means that when
buffers are killed, their storage will be returned to the operating system, 
and the size of the emacs process will shrink.

CAVEAT: code which contains calls to certain `face' accessor functions will
need to be recompiled by version 19.9 before it will work.  The functions
whose callers must be recompiled are: face-font, face-foreground,
face-background, face-background-pixmap, and face-underline-p.  The symptom
of this problem is the error "Wrong type argument, arrayp, #<face ... >".
The .elc files generated by version 19.9 will work in 19.6 and 19.8, but
older .elc files which contain calls to these functions will not work in 19.9.

Work In Progress:

 - We have been in the process of internationalizing Lucid Emacs.  This code is
   ***not*** ready for general use yet.  However, the code is included (and
   turned off by default) in this release.

   - If you define I18N2 at compile-time, then sorting/collation will be done
     according to the locale returned by setlocale().

   - If you define I18N3 at compile-time, then all messages printed by lemacs
     will be filtered through the gettext() library routine, to enable the use
     of locale-specific translation catalogues.  The current implementation of
     this is quite dependent on Solaris 2, and has a very large impact on 
     existing code, therefore we are going to be making major changes soon.
     (You'll notice calls to `gettext' and `GETTEXT' scattered around much of
     the lisp and C code; ignore it, this will be going away.)

   - If you define I18N4 at compile-time, then lemacs will internally use a
     wide representation of characters, enabling the use of large character
     sets such as Kanji.  This code is very OS dependent: it requires X11R5, 
     and several OS-supplied library routines for reading and writing wide
     characters (getwc(), putwc(), and a few others.)  Performance is also a
     problem.  This code is also scheduled for a major overhaul, with the
     intent of improving performance and portability.  

     Our eventual goal is to merge with MULE, or at least provide the same base
     level of functionality.  If you would like to help out with this, let us 
     know.

 - Other work-in-progress includes Motif drag-and-drop support, ToolTalk 
   support, and support for embedding an Emacs widget inside another 
   application (where it can function as that other application's text-entry
   area).  This code has not been extensively tested, and may (or may not)
   have portability problems, but it's there for the adventurous.  Comments, 
   suggestions, bug reports, and especially fixes are welcome.  But have no
   expectations that this experimental code will work at all.


** Major Differences Between 19.6 and 19.8
==========================================

There were almost no differences between versions 19.6 and 19.7; version 19.7
was a bug-fix release that was distributed with Energize 2.1.

Lucid Emacs 19.8 represents the first stage of the Lucid Emacs/Epoch merger.
The redisplay engine now in lemacs is an improved descendant of the Epoch
redisplay.  As a result, many bugs have been eliminated, and several disabled
features have been re-enabled.  Notably:

Selective display (and outline-mode) work.

Horizontally split windows work.

The height of a line is the height of the tallest font displayed on that line;
it is possible for a screen to display lines of differing heights. (Previously,
the height of all lines was the height of the tallest font loaded.)

There is lisp code to scale fonts up and down, for example, to load the next-
taller version of a font.

There is a new internal representation for lisp objects, giving emacs-lisp 28
bit integers and a 28 bit address space, up from the previous maximum of 26.
We expect eventually to increase this to 30 bit integers and a 32 bit address
space, eliminating the need for DATA_SEG_BITS on some architectures.  (On 64
bit machines, add 32 to all of these numbers.)

GC performance is improved.

Various X objects (fonts, colors, cursors, pixmaps) are accessible as first-
class lisp objects, with finalization.

An alternate interface to embedding images in the text is provided, called
"annotations."  You may create an "annotation margin" which is whitespace at
the left side of the screen that contains only annotations, not buffer text.

When using XPM files, one can specify the values of logical color names to be
used when loading the files.

It is possible to resize windows by dragging their modelines up and down.  More
generally, it is possible to add bindings for mouse gestures on the modelines.

There is support for playing sound files on HP machines.

ILISP version 5.5 is included.

The Common Lisp #' read syntax is supported (#' is to "function" as ' is to
"quote".)

The `active-p' slot of menu items is now evaluated, so one can put arbitrary
lisp code in a menu to decide whether that item should be selectable, rather
than doing this with an `activate-menubar-hook'.

The X resource hierarchy has changed slightly, to be more consistent.  It used
to be
        argv[0]                 SCREEN-NAME     pane    screen
        ApplicationShell        EmacsShell      Paned   EmacsFrame

   now it is

        argv[0]                 shell           pane    SCREEN-NAME
        ApplicationShell        EmacsShell      Paned   EmacsFrame

The Lucid Emacs sources have been largely merged with FSF version 19; this
means that the lisp library contains the most recent releases of various
packages, and many new features of FSF 19 have been incorporated.

Because of this, the lemacs sources should also be substantially more portable.


** Major Differences Between 19.4 and 19.6
==========================================

There were almost no differences between versions 19.4 and 19.5; we fixed
a few minor bugs and repacked 19.4 as 19.5 for a CD-ROM that we gave away
as a trade show promotion.

The primary goal of the 19.6 release is stability, rather than improved
functionality, so there aren't many user-visible changes.  The most notable
changes are:

 - The -geometry command-line option now correctly overrides geometry
   specifications in the resource database.
 - The `width' and `height' screen-parameters work.
 - Font-lock-mode considers the comment start and end characters to be
   a part of the comment.
 - The lhilit package has been removed.  Use font-lock-mode instead.
 - vm-isearch has been fixed to work with isearch-mode.
 - new versions of ispell and calendar.
 - sccs.el has menus.

Lots of bugs were fixed, including the problem that lemacs occasionally
grabbed the keyboard focus.

Also, as of Lucid Emacs 19.6 and Energize 2.0 (shipping now) it is possible
to compile the public release of Lucid Emacs with support for Energize; so
now Energize users will be able to build their own Energize-aware versions
of lemacs, and will be able to use newer versions of lemacs as they are
released to the net.  (Of course, this is not behavior covered by your
Energize support contract; you do it at your own risk.)

I have not incorporated all portability patches that I have been sent since
19.4; I will try to get to them soon.  However, if you need to make any
changes to lemacs to get it to compile on your system, it would be quite
helpful if you would send me context diffs (diff -c) against version 19.6.


** Major Differences Between 19.3 and 19.4
==========================================

Prototypes have been added for all functions.  Emacs compiles in the strict
ANSI modes of lcc and gcc, so portability should be vastly improved.

Many many many many core leaks have been plugged, especially in screen 
creation and deletion.

The float support reworked to be more portable and ANSI conformant.  This
resulted in these new configuration parameters: HAVE_INVERSE_HYPERBOLIC, 
HAVE_CBRT, HAVE_RINT, FLOAT_CHECK_ERRNO, FLOAT_CATCH_SIGILL, 
FLOAT_CHECK_DOMAIN.  Let us know if you had to change the defaults on your
architecture.

The SunOS unexec has been rewritten, and now works with either static or 
dynamic libraries, depending on whether -Bstatic or -Bdynamic were specified
at link-time.

Small (character-sized) bitmaps can be mixed in with buffer text via the new
functions set-extent-begin-glyph and set-extent-end-glyph.  (This is actually
a piece of functionality that Energize has been using for a while, but we've
just gotten around to making it possible to use it without Energize.  See how
nice we are?  Go buy our product.)

If compiled with Motif support, one can pop up dialog boxes from emacs lisp.
We encourage someone to contribute Athena an version of this code; it
shouldn't be much work.  

If dialog boxes are available, then y-or-n-p and yes-or-no-p use dialog boxes
instead of the minibuffer if invoked as a result of a command that was 
executed from a menu instead of from the keyboard.

Multiple screen support works better; check out doc of get-screen-for-buffer.

The default binding of backspace is the same as delete.  (C-h is still help.)

A middle click while the minibuffer is active does completion if you click on 
a highlighted completion, otherwise it executes the global binding of button2.

New versions of Barry Warsaw's c++-mode and syntax.c.  Font-lock-mode works
with C++ mode now.

The semantics of activate-menubar-hook has changed; the functions are called
with no arguments now.

`truename' no longer hacks the automounter; use directory-abbrev-alist instead.

Most minibuffer handling has been reimplemented in emacs-lisp.

There is now a builtin minibuffer history mechanism which replaces gmhist.


** Major Differences Between 19.2 and 19.3
==========================================

The ISO characters have correct case and syntax tables now, so the word-motion
and case-converting commands work sensibly on them.

If you set ctl-arrow to an integer, you can control exactly which characters
are printable.  (There will be a less crufty way to do this eventually.)

Menubars can now be buffer local; the function set-screen-menubar no longer
exists.  Look at GNUS and VM for examples of how to do this, or read 
menubar.el.

When emacs is reading from the minibuffer with completions, any completions
which are visible on the screen will highlight when the mouse moves over them;
clicking middle on a completion is the same as typing it at the minibuffer.
Some implications of this:  The *Completions* buffer is always mousable.  If
you're using the completion feature of find-tag, your source code will be
mousable when you type M-.  Dired buffers will be mousable as soon as you 
type ^X^F.  And so on.

The old isearch code has been replaced with a descendant of Dan LaLiberte's
excellent isearch-mode; it is more customizable, and generally less bogus.
You can search for "composed" characters.  There are new commands, too; see
the doc for ^S, or the NEWS file.

A patched GNUS 3.14 is included.

The user's manual now documents Lucid Emacs 19.3.

A few more modes have mouse and menu support.

The startup code should be a little more robust, and give you more reasonable
error messages when things aren't installed quite right (instead of the
ubiquitous "cannot open DISPLAY"...)

Subdirectories of the lisp directory whose names begin with a hyphen or dot
are not automatically added to the load-path, so you can use this to avoid
accidentally inflicting experimental software on your users.

I've tried to incorporate all of the portability patches that were sent to
me; I tried to solve some of the problems in different ways than the 
patches did, so let me know if I missed something.

Some systems will need to define NEED_STRDUP, NEED_REALPATH, HAVE_DREM, or
HAVE_REMAINDER in config.h.  Really this should be done in the appropriate
s- or m- files, but I don't know which systems need these and which don't.
If yours does, let me know which file it should be in.

Check out these new packages:

blink-paren.el: causes the matching parenthesis to flash on and off whenever
                the cursor is sitting on a paren-syntax character.

pending-del.el: Certain commands implicitly delete the highlighted region:
                Typing a character when there is a highlighted region replaces
                that region with the typed character.

font-lock.el:   A code-highlighting package, driven off of syntax tables, so
                that it understands block comments, strings, etc.  The 
                insertion hook is used to fontify text as you type it in.

shell-font.el:  Displays your shell-buffer prompt in boldface.

* The History of XEmacs
=======================

This product is an extension of GNU Emacs, previously known to some as
"Lucid Emacs" or "ERA".  It was initially based on an early version of Emacs
Version 19 from the Free Software Foundation and has since been kept
up-to-date with recent versions of that product.  It stems from a
collaboration of Lucid, Inc. with SunSoft DevPro (a division of Sun
Microsystems, Inc.; formerly called SunPro) and the University of Illinois.

NOTE: Lucid, Inc. is currently out of business but development on XEmacs
continues strong.  Recently, Amdahl Corporation and INS Engineering have
both contributed significantly to the development of XEmacs.


* What's Different?
===================


** Differences between XEmacs and GNU Emacs 19
==================================================
In XEmacs 20, characters are first-class objects.  Characters can be
converted to integers, but are not integers.  FSF 19, XEmacs 19, and Mule
represent them as integers.

In XEmacs, events are first-class objects.  FSF 19 represents them as
integers, which obscures the differences between a key gesture and the
ancient ASCII code used to represent a particular overlapping subset of them.

In XEmacs, keymaps are first-class opaque objects.  FSF 19 represents them as
complicated combinations of association lists and vectors.  If you use the
advertised functional interface to manipulation of keymaps, the same code
will work in XEmacs, Emacs 18, and GNU Emacs 19; if your code depends
on the underlying implementation of keymaps, it will not.

XEmacs uses "extents" to represent all non-textual aspects of buffers;
FSF 19 uses two distinct objects, "text properties" and "overlays",
which divide up the functionality between them.  Extents are a
superset of the functionality of the two FSF data types.  The full FSF
19 interface to text properties and overlays is supported in XEmacs
(with extents being the underlying representation).

Extents can be made to be copied into strings, and thus restored by kill
and yank.  Thus, one can specify this behavior on either "extents" or
"text properties", whereas in FSF 19 text properties always have this
behavior and overlays never do.

Many more packages are provided standard with XEmacs than with FSF 19.

Images of arbitrary size can be embedded in a buffer.

Variable width fonts work.

The height of a line is the height of the tallest font on that line, instead
of all lines having the same height.

XEmacs uses the MIT "Xt" toolkit instead of raw Xlib calls, which
makes it be a more well-behaved X citizen (and also improves
portability).  A result of this is that it is possible to include
other Xt "Widgets" in the XEmacs window.  Also, XEmacs understands the
standard Xt command-line arguments.

XEmacs provides support for ToolTalk on systems that have it.

XEmacs can ask questions using popup dialog boxes.  Any command executed from
a menu will ask yes/no questions with dialog boxes, while commands executed
via the keyboard will use the minibuffer.

XEmacs has a built-in toolbar.  Four toolbars can actually be configured:
top, bottom, left, and right toolbars.

XEmacs has vertical and horizontal scrollbars.  Unlike in FSF 19 (which
provides a primitive form of vertical scrollbar), these are true toolkit
scrollbars.  A look-alike Motif scrollbar is provided for those who
don't have Motif. (Even for those who do, the look-alike may be preferable
as it is faster.)

If you're running on a machine with audio hardware, you can specify sound 
files for XEmacs to play instead of the default X beep.  See the documentation
of the function load-sound-file and the variable sound-alist.

An XEmacs frame can be placed within an "external client widget" managed by
another application.  This allows an application to use an XEmacs frame as its
text pane rather than the standard Text widget that is provided with Motif or
Athena.  XEmacs supports Motif applications, generic Xt (e.g. Athena)
applications, and raw Xlib applications.

Here are some more specifics about the XEmacs implementation:

*** The Input Model
-------------------

The fundamental unit of input is an "event" instead of a character.  An
event is a new data type that contains several pieces of information.
There are several kinds of event, and corresponding accessor and utility
functions.  We tried to abstract them so that they would apply equally
well to a number of window systems.

NOTE: All timestamps are measured as milliseconds since Emacs started.

 key_press_event	
    event_channel	A token representing which keyboard generated it.
			For this kind of event, this is a console object.
    timestamp		When it happened
    key			What keysym this is; a character or a symbol.
			If it is a character, it will be a printing
			ASCII character.
    modifiers		Bucky-bits on that key: control, meta, etc.
			For most keys, Shift is not a bit; that is implicit
			in the keyboard layout.

 button_press_event
 button_release_event
    event_channel	A token representing which mouse generated it.
			For this kind of event, this is a frame object.
    timestamp		When it happened
    button		What button went down or up.
    modifiers		Bucky-bits on that button: shift, control, meta, etc.
    x, y		Where it was at the button-state-change (in pixels).

 pointer_motion_event
    event_channel	A token representing which mouse generated it.
			For this kind of event, this is a frame object.
    timestamp		When it happened
    x, y		Where it was after it moved (in pixels).
    modifiers		Bucky-bits down when the motion was detected.
			(Possibly not all window systems will provide this?)

 process_event
    timestamp		When it happened
    process		the emacs "process" object in question

 timeout_event
    timestamp		Now (really, when the timeout was signaled)
    interval_id		The ID returned when the associated call to
			add_timeout_cb() was made
	------ the rest of the fields are filled in by Emacs -----
    id_number		The Emacs timeout ID for this timeout (more
			than one timeout event can have the same value
			here, since Emacs timeouts, as opposed to
			add_timeout_cb() timeouts, can resignal
			themselves)
    function		An elisp function to call when this timeout is
			processed.
    object		The object passed to that function.

 eval_event
    timestamp		When it happened
    function		An elisp function to call with this event object.
    object		Anything.
			This kind of event is used internally; sometimes the
			window system interface would like to inform emacs of
			some user action (such as focusing on another frame)
			but needs that to happen synchronously with the other
			user input, like keypresses.  This is useful when
			events are reported through callbacks rather
			than in the standard event stream.

 misc_user_event
    timestamp		When it happened
    function		An elisp function to call with this event object.
    object		Anything.
			This is similar to an eval_event, except that it is
			generated by user actions: selections in the
			menubar or scrollbar actions.  It is a "command"
			event, like key and mouse presses (and unlike mouse
			motion, process output, and enter and leave window
			hooks).  In many ways, eval_events are not the same
			as keypresses or misc_user_events.

 magic_event
			No user-serviceable parts within.  This is for things
			like KeymapNotify and ExposeRegion events and so on
			that emacs itself doesn't care about, but which it
			must do something with for proper interaction with
			the window system.

			Magic_events are handled somewhat asynchronously, just
			like subprocess filters.  However, occasionally a 
			magic_event needs to be handled synchronously; in that
			case, the asynchronous handling of the magic_event will
			push an eval_event back onto the queue, which will be 
			handled synchronously later.  This is one of the
			reasons why eval_events exist; I'm not entirely happy
			with this aspect of this event model.


The function `next-event' blocks and returns one of the above-described 
event objects.  The function `dispatch-event' takes an event and processes
it in the appropriate way.

For a process-event, dispatch-event calls the process's handler; for a
mouse-motion event, the mouse-motion-handler hook is called, and so on.
For magic-events, dispatch-event does window-system-dependent things,
including calling some non-window-system-dependent hooks: map-frame-hook,
unmap-frame-hook, mouse-enter-frame-hook, and mouse-leave-frame-hook.

The function `next-command-event' calls `next-event' until it gets a key or
button from the user (that is, not a process, motion, timeout, or magic
event).  If it gets an event that is not a key or button, it calls
`dispatch-event' on it immediately and reads another one.  The
next-command-event function could be implemented in Emacs Lisp, though it
isn't.  Generally one should call `next-command-event' instead of
`next-event'.

read-char calls next-command-event; if it doesn't get an event that can be
converted to an ASCII character, it signals an error.  Otherwise it returns
an integer.

The variable `last-command-char' always contains an integer, or nil (if the
last read event has no ASCII equivalent, as when it is a mouse-click or a
non-ASCII character chord.)

The new variable `last-command-event' holds an event object, that could be
a non-ASCII character, a button click, a menu selection, etc.

The variable `unread-command-char' no longer exists, and has been replaced
by `unread-command-events'.  With the new event model, it is incorrect for
code to do (setq unread-command-char (read-char)), because all user-input
can't be represented as ASCII characters.  *** This is an incompatible 
change.  Code which sets `unread-command-char' must be updated to use the
combination of `next-command-event' and `unread-command-events' instead.

The functions `this-command-keys' and `recent-keys' return a vector of
event objects, instead of a string of ASCII characters.  *** This also
is an incompatible change.

Almost nothing happens at interrupt level; the SIGIO handler simply sets a
flag, and later, the X event queue is scanned for KeyPress events which map
to ^G.  All redisplay happens in the main thread of the process.


*** Keymaps
-----------

Instead of keymaps being alists or obarrays, they are a new primary data
type.  The only user access to the contents of a keymap is through the
existing keymap-manipulation functions, and a new function, map-keymap.
This means that existing code that manipulates keymaps may need to 
be changed.

One of our goals with the new input and keymap code was to make more
character combinations available for binding, besides just ASCII and
function keys.  We want to be able bind different commands to Control-a 
and Control-Shift-a; we also want it to be possible for the keys Control-h
and Backspace (and Control-M and Return, and Control-I and Tab, etc) to
be distinct.

One of the most common complaints that new Emacs users have is that backspace
is help.  The answer is to play around with the keyboard-translate-table, or
be lucky enough to have a system administrator who has done this for you
already; but if it were possible to bind backspace and C-h to different
things, then (under a window manager at least) both backspace and delete
would delete a character, and ^H would be help.  There's no need to deal 
with xmodmap, kbd-translate-table, etc.

Here are some more examples: suppose you want to bind one function to Tab, 
and another to Control-Tab.  This can't be done if Tab and Control-I are the
same thing.  What about control keys that have no ASCII equivalent, like
Control-< ?  One might want that to be bound to set-mark-at-point-min.  We
want M-C-Backspace to be kill-backward-sexp.  But we want M-Backspace to be
kill-backward-word.  Again, this can't be done if Backspace and C-h are
indistinguishable.

The user represents keys as a string of ASCII characters (when possible and
convenient), or as a vector of event objects, or as a vector of "key 
description lists", that looks like (control a), or (control meta delete) 
or (shift f1).  The order of the modifier-names is not significant, so
(meta control x) and (control meta x) are the same.

`define-key' knows how to take any of the above representations and store them
into a keymap.  When Emacs wants to return a key sequence (this-command-keys,
recent-keys, keyboard-macros, and read-key-sequence, for example) it returns
a vector of event objects.  Keyboard macros can also be represented as ASCII
strings or as vectors of key description lists.  

This is an incompatible change: code which calls `this-command-keys',
`recent-keys', `read-key-sequence', or manipulates keyboard-macros probably
needs to be changed so that it no longer assumes that the returned value is a
string.

Control-Shift-a is specified as (control A), not (control shift a), since A
is a two-case character.  But for keys that don't have an upper case
version, like F1, Backspace, and Escape, you use the (shift backspace) syntax.

See the doc string for our version of define-key, reproduced below in the
`Changed Functions' section.  Note that when the KEYS argument is a string,
it has the same semantics as the v18 define-key.


*** Xt Integration
------------------

The heart of the event loop is implemented in terms of the Xt event functions
(specifically XtAppProcessEvent), and uses Xt's concept of timeouts and
file-descriptor callbacks, eliminating a large amount of system-dependent code
(Xt does it for you.)

If Emacs is compiled with support for X, it uses the Xt event loop even when
Emacs is not running on an X display (the Xt event loop supports this).  This
makes it possible to run Emacs on a dumb TTY, and later connect it to one or
more X servers.  It should also be possible to later connect an existing Emacs
process to additional TTY's, although this code is still experimental.  (Our
intent at this point is not to have an Emacs that is being used by multiple
people at the same time: it is to make it possible for someone to go home, log
in on a dialup line, and connect to the same Emacs process that is running
under X in their office without having to recreate their buffer state and so
on.)

If Emacs is not compiled with support for X, then it instead uses more general
code, something like what v18 does; but this way of doing things is a lot more
modular.

(Linking Emacs with Xt seems to only add about 300k to the executable size,
compared with an Emacs linked with Xlib only.)


*** Region Highlighting
-----------------------

If the variable `zmacs-regions' is true, then the region between point and
mark will be highlighted when "active".  Those commands which push a mark
(such as C-SPC, and C-x C-x) make the region become "active" and thus
highlighted.  Most commands (all non-motion commands, basically) cause it to
become non-highlighted (non-"active").  Commands that operate on the region
(such as C-w, C-x C-l, etc.) only work if the region is in the highlighted
state.

zmacs-activate-region-hook and zmacs-deactivate-region-hook are run at the
appropriate times; under X, zmacs-activate-region-hook makes the X selection
be the region between point and mark, thus doing two things at once: making
the region and the X selection be the same; and making the region highlight
in the same way as the X selection.

If `zmacs-regions' is true, then the `mark-marker' command returns nil unless
the region is currently in the active (highlighted) state.  With an argument
of t, this returns the mark (if there is one) regardless of the active-region
state.  You should *generally* not use the mark unless the region is active,
if the user has expressed a preference for the active-region model.  Watch
out!  Moving this marker changes the mark position.  If you set the marker not
to point anywhere, the buffer will have no mark.

In this way, the primary selection is a fairly transitory entity; but
when something is copied to the kill ring, it is made the Clipboard
selection.  It is also stored into CUT_BUFFER0, for compatibility with
X applications that don't understand selections (like Emacs18).

Compatibility note: if you have code which uses (mark) or (mark-marker),
then you need to either: change those calls to (mark t) or (mark-marker t);
or simply bind `zmacs-regions' to nil around the call to mark or mark-marker.
This is probably the best solution, since it will work in Emacs 18 as well.


*** Menubars and Dialog Boxes
-----------------------------

Here is an example of a menubar definition:

(defvar default-menubar
  '(("File"     ["Open File..."         find-file               t]
                ["Save Buffer"          save-buffer             t]
                ["Save Buffer As..."    write-file              t]
                ["Revert Buffer"        revert-buffer           t]
                "-----"
                ["Print Buffer"         lpr-buffer              t]
                "-----"
                ["Delete Frame"         delete-frame            t]
                ["Kill Buffer..."       kill-buffer             t]
                ["Exit Emacs"           save-buffers-kill-emacs t]
                )
    ("Edit"     ["Undo"                 advertised-undo         t]
                ["Cut"                  kill-primary-selection  t]
                ["Copy"                 copy-primary-selection  t]
                ["Paste"                yank-clipboard-selection t]
                ["Clear"                delete-primary-selection t]
                )
    ...))

The first element of each menu item is the string to print on the menu.

The second element is the callback function; if it is a symbol, it is
invoked with `call-interactively.'  If it is a list, it is invoked with
`eval'.  

If the second element is a symbol, then the menu also displays the key that
is bound to that command (if any).

The third element of the menu items determines whether the item is selectable.
It may be t, nil, or a form to evaluate.  Also, a hook is run just before a
menu is exposed, which can be used to change the value of these slots. 
For example, there is a hook that makes the "undo" menu item be selectable
only in the cases when `advertised-undo' would not signal an error.  

Menus may have other menus nested within them; they will cascade.

There are utility functions for adding items to menus, deleting items,
disabling them, etc.

The function `popup-menu' takes a menu description and pops it up.  

The function `popup-dialog-box' takes a dialog-box description and pops 
it up.  Dialog box descriptions look a lot like menu descriptions.

The menubar, menu, and dialog-box code is implemented as a library, 
with an interface which hides the toolkit that implements it.  


*** Isearch Changes
-------------------

Isearch has been reimplemented in a different way, adding some new features,
and causing a few incompatible changes.

 -  the old isearch-*-char variables are no longer supported.  In the old
    system, one could make ^A mean "repeat the search" by doing something
    like (setq search-repeat-char ?C-a).  In the new system, this is 
    accomplished with 

       (define-key isearch-mode-map "\C-a" 'isearch-repeat-forward)

 -  The advantage of using the normal keymap mechanism for this is that you
    can bind more than one key to an isearch command: for example, both C-a
    and C-s could do the same thing inside isearch mode.  You can also bind
    multi-key sequences inside of isearch mode, and bind non-ASCII keys.
    For example, to use the F1 key to terminate a search:

       (define-key isearch-mode-map 'f1 'isearch-exit)

    or to make ``C-c C-c'' terminate a search:

       (define-key isearch-mode-map "\C-c\C-c" 'isearch-exit)

 -  If isearch is behaving case-insensitively (the default) and you type an
    upper case character, then the search will become case-sensitive.  This
    can be disabled by setting `search-caps-disable-folding' to nil.

 -  There is a history ring of the strings previously searched for; typing
    M-p or M-n while searching will cycle through this ring.  Typing M-TAB
    will do completion across the set of items in the history ring.

 -  The ESC key is no longer used to terminate an incremental search.  The
    RET key should be used instead.  This change is necessary for it to be
    possible to bind "meta" characters to isearch commands.


*** Startup Code Changes
------------------------

The initial X frame is mapped before the user's .emacs file is executed.
Without this, there is no way for the user to see any error messages
generated by their .emacs file, any windows created by the .emacs file
don't show up, and the copyleft notice isn't shown.

The default values for load-path, exec-path, lock-directory, and
Info-directory-list are not (necessarily) built into Emacs, but are
computed at startup time.  

First, Emacs looks at the directory in which its executable file resides:

  o  If that directory contains subdirectories named "lisp" and "lib-src",
     then those directories are used as the lisp library and exec directory.

  o  If the parent of the directory in which the emacs executable is located
     contains "lisp" and "lib-src" subdirectories, then those are used.

  o  If ../lib/xemacs-<version> (starting from the directory in which the
     emacs executable is located) contains a "lisp" subdirectory and either
     a "lib-src" subdirectory or a <configuration-name> subdirectory, then
     those are used.

  o  If the emacs executable that was run is a symbolic link, then the link
     is chased, and the resultant directory is checked as above.

(Actually, it doesn't just look for "lisp/", it looks for "lisp/prim/",
which reduces the chances of a false positive.)

If the lisp directory contains subdirectories, they are added to the default
load-path as well.  If the site-lisp directory exists and contains
subdirectories, they are then added.  Subdirectories whose names begin with
a dot or a hyphen are not added to the load-path.

These heuristics fail if the Emacs binary was copied from the main Emacs
tree to some other directory, and links for the lisp directory were not put
in.  This isn't much of a restriction: either make there be subdirectories
(or symbolic links) of the directory of the emacs executable, or make the
"installed" emacs executable be a symbolic link to an executable in a more
appropriate directory structure.  For example, this setup works:

    /usr/local/xemacs/xemacs*           ; The executable.
    /usr/local/xemacs/lisp/             ; The associated directories.
    /usr/local/xemacs/etc/              ; Any of the files in this list
    /usr/local/xemacs/lock/             ; could be symbolic links as well.
    /usr/local/xemacs/info/

As does this:

    /usr/local/bin/xemacs -> ../xemacs/src/xemacs-19.14 ; A link...
    /usr/local/xemacs/src/xemacs-19.14*                 ; The executable,
    /usr/local/xemacs/lisp/                             ; and the rest of
    /usr/local/xemacs/etc/                              ; the source tree
    /usr/local/xemacs/lock/
    /usr/local/xemacs/info/

This configuration might be used for a multi-architecture installation; assume
that $LOCAL refers to a directory which contains only files specific to a 
particular architecture (i.e., executables) and $SHARED refers to those files 
which are not machine specific (i.e., lisp code and documentation.)

    $LOCAL/bin/xemacs@ -> $LOCAL/xemacs-19.14/xemacs*
    $LOCAL/xemacs-19.14/lisp@ -> $SHARED/xemacs-19.14/lisp/
    $LOCAL/xemacs-19.14/etc@  -> $SHARED/xemacs-19.14/etc/
    $LOCAL/xemacs-19.14/info@ -> $SHARED/xemacs-19.14/info/

The following would also work, but the above is probably more attractive:

    $LOCAL/bin/xemacs*
    $LOCAL/bin/lisp@ -> $SHARED/xemacs-19.14/lisp/
    $LOCAL/bin/etc@  -> $SHARED/xemacs-19.14/etc/
    $LOCAL/bin/info@ -> $SHARED/xemacs-19.14/info/

If Emacs can't find the requisite directories, it writes a message like this
(or some appropriate subset of it) to stderr:

  WARNING:
  couldn't find an obvious default for load-path, exec-directory, and
  lock-directory, and there were no defaults specified in paths.h when
  Emacs was built.  Perhaps some directories don't exist, or the Emacs
  executable, /cadillac-th/jwz/somewhere/xemacs is in a strange place?

  Without both exec-directory and load-path, Emacs will be very broken.
  Consider making a symbolic link from /cadillac-th/jwz/somewhere/etc
  to wherever the appropriate Emacs etc/ directory is, and from
  /cadillac-th/jwz/somewhere/lisp/ to wherever the appropriate Emacs
  lisp library is.

  Without lock-directory set, file locking won't work.  Consider
  creating /cadillac-th/jwz/somewhere/lock as a directory or symbolic
  link for use as the lock directory.

The default installation tree is the following:

    /usr/local/bin/b2m                          ;
                   ctags                        ; executables that
                   emacsclient                  ; should be in
                   etags                        ; user's path
                   xemacs -> xemacs-<version>   ;
                   xemacs                       ;
    /usr/local/lib/xemacs/site-lisp
    /usr/local/lib/xemacs/lock
    /usr/local/lib/xemacs-<version>/etc         ; architecture ind. files
    /usr/local/lib/xemacs-<version>/info
    /usr/local/lib/xemacs-<version>/lisp
    /usr/local/lib/xemacs-<version>/<configuration>  ; binaries emacs may run


*** X Resources
---------------

(Note: This section is copied verbatim from the XEmacs Reference Manual.)

   The Emacs resources are generally set per-frame. Each Emacs frame
can have its own name or the same name as another, depending on the
name passed to the `make-frame' function.

   You can specify resources for all frames with the syntax:

     Emacs*parameter: value

or

     Emacs*EmacsFrame.parameter:value

You can specify resources for a particular frame with the syntax:

     Emacs*FRAME-NAME.parameter: value


**** Geometry Resources
-----------------------

   To make the default size of all Emacs frames be 80 columns by 55
lines, do this:

     Emacs*EmacsFrame.geometry: 80x55

To set the geometry of a particular frame named `fred', do this:

     Emacs*fred.geometry: 80x55

Important! Do not use the following syntax:

     Emacs*geometry: 80x55

You should never use `*geometry' with any X application. It does not
say "make the geometry of Emacs be 80 columns by 55 lines."  It really
says, "make Emacs and all subwindows thereof be 80x55 in whatever units
they care to measure in."  In particular, that is both telling the
Emacs text pane to be 80x55 in characters, and telling the menubar pane
to be 80x55 pixels, which is surely not what you want.

   As a special case, this geometry specification also works (and sets
the default size of all Emacs frames to 80 columns by 55 lines):

     Emacs.geometry: 80x55

since that is the syntax used with most other applications (since most
other applications have only one top-level window, unlike Emacs).  In
general, however, the top-level shell (the unmapped ApplicationShell
widget named `Emacs' that is the parent of the shell widgets that
actually manage the individual frames) does not have any interesting
resources on it, and you should set the resources on the frames instead.

   The `-geometry' command-line argument sets only the geometry of the
initial frame created by Emacs.

   A more complete explanation of geometry-handling is

   * The `-geometry' command-line option sets the `Emacs.geometry'
     resource, that is, the geometry of the ApplicationShell.

   * For the first frame created, the size of the frame is taken from
     the ApplicationShell if it is specified, otherwise from the
     geometry of the frame.

   * For subsequent frames, the order is reversed: First the frame, and
     then the ApplicationShell.

   * For the first frame created, the position of the frame is taken
     from the ApplicationShell (`Emacs.geometry') if it is specified,
     otherwise from the geometry of the frame.

   * For subsequent frames, the position is taken only from the frame,
     and never from the ApplicationShell.

   This is rather complicated, but it does seem to provide the most
intuitive behavior with respect to the default sizes and positions of
frames created in various ways.


**** Iconic Resources
---------------------

   Analogous to `-geometry', the `-iconic' command-line option sets the
iconic flag of the ApplicationShell (`Emacs.iconic') and always applies
to the first frame created regardless of its name.  However, it is
possible to set the iconic flag on particular frames (by name) by using
the `Emacs*FRAME-NAME.iconic' resource.


**** Resource List
------------------

   Emacs frames accept the following resources:

`geometry' (class `Geometry'): string
     Initial geometry for the frame.  *Note Geometry Resources:: for a
     complete discussion of how this works.

`iconic' (class `Iconic'): boolean
     Whether this frame should appear in the iconified state.

`internalBorderWidth' (class `InternalBorderWidth'): int
     How many blank pixels to leave between the text and the edge of the
     window.

`interline' (class `Interline'): int
     How many pixels to leave between each line (may not be
     implemented).

`menubar' (class `Menubar'): boolean
     Whether newly-created frames should initially have a menubar.  Set
     to true by default.

`initiallyUnmapped' (class `InitiallyUnmapped'): boolean
     Whether XEmacs should leave the initial frame unmapped when it
     starts up.  This is useful if you are starting XEmacs as a server
     (e.g. in conjunction with gnuserv or the external client widget).
     You can also control this with the `-unmapped' command-line option.

`barCursor' (class `BarColor'): boolean
     Whether the cursor should be displayed as a bar, or the
     traditional box.

`textPointer' (class `Cursor'): cursor-name
     The cursor to use when the mouse is over text.  This resource is
     used to initialize the variable `x-pointer-shape'.

`selectionPointer' (class `Cursor'): cursor-name
     The cursor to use when the mouse is over a selectable text region
     (an extent with the `highlight' property; for example, an Info
     cross-reference).  This resource is used to initialize the variable
     `x-selection-pointer-shape'.

`spacePointer' (class `Cursor'): cursor-name
     The cursor to use when the mouse is over a blank space in a buffer
     (that is, after the end of a line or after the end-of-file).  This
     resource is used to initialize the variable
     `x-nontext-pointer-shape'.

`modeLinePointer' (class `Cursor'): cursor-name
     The cursor to use when the mouse is over a mode line.  This
     resource is used to initialize the variable `x-mode-pointer-shape'.

`gcPointer' (class `Cursor'): cursor-name
     The cursor to display when a garbage-collection is in progress.
     This resource is used to initialize the variable
     `x-gc-pointer-shape'.

`scrollbarPointer' (class `Cursor'): cursor-name
     The cursor to use when the mouse is over the scrollbar.  This
     resource is used to initialize the variable
     `x-scrollbar-pointer-shape'.

`pointerColor' (class `Foreground'): color-name
`pointerBackground' (class `Background'): color-name
     The foreground and background colors of the mouse cursor.  These
     resources are used to initialize the variables
     `x-pointer-foreground-color' and `x-pointer-background-color'.

`scrollBarWidth' (class `ScrollBarWidth'): integer
     How wide the vertical scrollbars should be, in pixels; 0 means no
     vertical scrollbars.  You can also use a resource specification of
     the form `*scrollbar.width', or the usual toolkit scrollbar
     resources: `*XmScrollBar.width' (Motif), `*XlwScrollBar.width'
     (Lucid), or `*Scrollbar.thickness' (Athena).  We don't recommend
     that you use the toolkit resources, though, because they're
     dependent on how exactly your particular build of XEmacs was
     configured.

`scrollBarHeight' (class `ScrollBarHeight'): integer
     How high the horizontal scrollbars should be, in pixels; 0 means no
     horizontal scrollbars.  You can also use a resource specification
     of the form `*scrollbar.height', or the usual toolkit scrollbar
     resources: `*XmScrollBar.height' (Motif), `*XlwScrollBar.height'
     (Lucid), or `*Scrollbar.thickness' (Athena).  We don't recommend
     that you use the toolkit resources, though, because they're
     dependent on how exactly your particular build of XEmacs was
     configured.

`scrollBarPlacement' (class `ScrollBarPlacement'): string
     Where the horizontal and vertical scrollbars should be positioned.
     This should be one of the four strings `bottom-left',
     `bottom-right', `top-left', and `top-right'.  Default is
     `bottom-right' for the Motif and Lucid scrollbars and
     `bottom-left' for the Athena scrollbars.

`topToolBarHeight' (class `TopToolBarHeight'): integer
`bottomToolBarHeight' (class `BottomToolBarHeight'): integer
`leftToolBarWidth' (class `LeftToolBarWidth'): integer
`rightToolBarWidth' (class `RightToolBarWidth'): integer
     Height and width of the four possible toolbars.

`topToolBarShadowColor' (class `TopToolBarShadowColor'): color-name
`bottomToolBarShadowColor' (class `BottomToolBarShadowColor'): color-name
     Color of the top and bottom shadows for the toolbars.  NOTE: These
     resources do *not* have anything to do with the top and bottom
     toolbars (i.e. the toolbars at the top and bottom of the frame)!
     Rather, they affect the top and bottom shadows around the edges of
     all four kinds of toolbars.

`topToolBarShadowPixmap' (class `TopToolBarShadowPixmap'): pixmap-name
`bottomToolBarShadowPixmap' (class `BottomToolBarShadowPixmap'): pixmap-name
     Pixmap of the top and bottom shadows for the toolbars.  If set,
     these resources override the corresponding color resources. NOTE:
     These resources do *not* have anything to do with the top and
     bottom toolbars (i.e. the toolbars at the top and bottom of the
     frame)!  Rather, they affect the top and bottom shadows around the
     edges of all four kinds of toolbars.

`toolBarShadowThickness' (class `ToolBarShadowThickness'): integer
     Thickness of the shadows around the toolbars, in pixels.

`visualBell' (class `VisualBell'): boolean
     Whether XEmacs should flash the screen rather than making an
     audible beep.

`bellVolume' (class `BellVolume'): integer
     Volume of the audible beep.

`useBackingStore' (class `UseBackingStore'): boolean
     Whether XEmacs should set the backing-store attribute of the X
     windows it creates.  This increases the memory usage of the X
     server but decreases the amount of X traffic necessary to update
     the screen, and is useful when the connection to the X server goes
     over a low-bandwidth line such as a modem connection.


**** Face Resources
-------------------

   The attributes of faces are also per-frame. They can be specified as:

     Emacs.FACE_NAME.parameter: value

     (*do not* use `Emacs*FACE_NAME...')

or

     Emacs*FRAME_NAME.FACE_NAME.parameter: value

Faces accept the following resources:

`attributeFont' (class `AttributeFont'): font-name
     The font of this face.

`attributeForeground' (class `AttributeForeground'): color-name
`attributeBackground' (class `AttributeBackground'): color-name
     The foreground and background colors of this face.

`attributeBackgroundPixmap' (class `AttributeBackgroundPixmap'): file-name
     The name of an XBM file (or XPM file, if your version of Emacs
     supports XPM), to use as a background stipple.

`attributeUnderline' (class `AttributeUnderline'): boolean
     Whether text in this face should be underlined.

   All text is displayed in some face, defaulting to the face named
`default'.  To set the font of normal text, use
`Emacs*default.attributeFont'. To set it in the frame named `fred', use
`Emacs*fred.default.attributeFont'.

   These are the names of the predefined faces:

`default'
     Everything inherits from this.

`bold'
     If this is not specified in the resource database, Emacs tries to
     find a bold version of the font of the default face.

`italic'
     If this is not specified in the resource database, Emacs tries to
     find an italic version of the font of the default face.

`bold-italic'
     If this is not specified in the resource database, Emacs tries to
     find a bold-italic version of the font of the default face.

`modeline'
     This is the face that the modeline is displayed in.  If not
     specified in the resource database, it is determined from the
     default face by reversing the foreground and background colors.

`highlight'
     This is the face that highlighted extents (for example, Info
     cross-references and possible completions, when the mouse passes
     over them) are displayed in.

`left-margin'
`right-margin'
     These are the faces that the left and right annotation margins are
     displayed in.

`zmacs-region'
     This is the face that mouse selections are displayed in.

`text-cursor'
     This is the face that the cursor is displayed in.

`isearch'
     This is the face that the matched text being searched for is
     displayed in.

`info-node'
     This is the face of info menu items.  If unspecified, it is copied
     from `bold-italic'.

`info-xref'
     This is the face of info cross-references.  If unspecified, it is
     copied from `bold'. (Note that, when the mouse passes over a
     cross-reference, the cross-reference's face is determined from a
     combination of the `info-xref' and `highlight' faces.)

   Other packages might define their own faces; to see a list of all
faces, use any of the interactive face-manipulation commands such as
`set-face-font' and type `?' when you are prompted for the name of a
face.

   If the `bold', `italic', and `bold-italic' faces are not specified
in the resource database, then XEmacs attempts to derive them from the
font of the default face.  It can only succeed at this if you have
specified the default font using the XLFD (X Logical Font Description)
format, which looks like

     *-courier-medium-r-*-*-*-120-*-*-*-*-*-*

If you use any of the other, less strict font name formats, some of
which look like

     lucidasanstypewriter-12
     fixed
     9x13

   then XEmacs won't be able to guess the names of the bold and italic
versions.  All X fonts can be referred to via XLFD-style names, so you
should use those forms.  See the man pages for `X(1)', `xlsfonts(1)',
and `xfontsel(1)'.


**** Widgets
------------

   There are several structural widgets between the terminal EmacsFrame
widget and the top level ApplicationShell; the exact names and types of
these widgets change from release to release (for example, they changed
in 19.9, 19.10, 19.12, and 19.13) and are subject to further change in
the future, so you should avoid mentioning them in your resource database.
The above-mentioned syntaxes should be forward-compatible.  As of 19.14,
the exact widget hierarchy is as follows:

    INVOCATION-NAME           "shell"              "container"     FRAME-NAME
    x-emacs-application-class "TopLevelEmacsShell" "EmacsManager" "EmacsFrame"

(for normal frames)

or

    INVOCATION-NAME           "shell"               "container"     FRAME-NAME
    x-emacs-application-class "TransientEmacsShell" "EmacsManager" "EmacsFrame"

(for popup/dialog-box frames)

where INVOCATION-NAME is the terminal component of the name of the
XEmacs executable (usually `xemacs'), and `x-emacs-application-class'
is generally `Emacs'.


**** Menubar Resources
----------------------

   As the menubar is implemented as a widget which is not a part of
XEmacs proper, it does not use the face mechanism for specifying fonts
and colors: It uses whatever resources are appropriate to the type of
widget which is used to implement it.

   If Emacs was compiled to use only the Motif-lookalike menu widgets,
then one way to specify the font of the menubar would be

     Emacs*menubar*font: *-courier-medium-r-*-*-*-120-*-*-*-*-*-*

   If the Motif library is being used, then one would have to use

     Emacs*menubar*fontList: *-courier-medium-r-*-*-*-120-*-*-*-*-*-*

   because the Motif library uses the `fontList' resource name instead
of `font', which has subtly different semantics.

   The same is true of the scrollbars: They accept whichever resources
are appropriate for the toolkit in use.


*** Source Code Highlighting
----------------------------

It's possible to have your buffers "decorated" with fonts or colors
indicating syntactic structures (such as strings, comments, function names,
"reserved words", etc.).  In XEmacs, the preferred way to do this is with
font-lock-mode; activate it by adding the following code to your .emacs file:

        (add-hook 'emacs-lisp-mode-hook 'turn-on-font-lock)
        (add-hook 'c-mode-hook          'turn-on-font-lock)
        (add-hook 'c++-mode-hook        'turn-on-font-lock)
        (add-hook 'dired-mode-hook      'turn-on-font-lock)
        ...etc...

To customize it, see the descriptions of the function `font-lock-mode' and
the variables `font-lock-keywords', `c-font-lock-keywords', etc.

There exist several other source code highlighting packages, but font-lock
does one thing that most others don't do: highlights as you type new text;
and one thing that no others do: bases part of its decoration on the
syntax table of the major mode.  Font-lock has C-level support to do this
efficiently, so it should also be significantly faster than the others.

If there's something that another highlighting package does that you can't
make font-lock do, let us know.  We would prefer to consolidate all of the
desired functionality into one package rather than ship several different
packages which do essentially the same thing in different ways.


** Differences Between XEmacs and Emacs 18
==========================================

Auto-configure support has been added, so it should be fairly easy to compile
XEmacs on different systems.  If you have any problems or feedback about
compiling on your system, please let us know.

We have reimplemented the basic input model in a more general way; instead of
X input being a special-case of the normal ASCII input stream, XEmacs has a
concept of "input events", and ASCII characters are a subset of that.  The
events that XEmacs knows about are not X events, but are a generalization of
them, so that XEmacs can eventually be ported to different window systems.

We have reimplemented keymaps so that sequences of events can be stored into
them instead of just ASCII codes; it is possible to, for example, bind
different commands to each of the chords Control-h, Control-H, Backspace,
Control-Backspace, and Super-Shift-Backspace.  Key bindings, function key
bindings, and mouse bindings live in the same keymaps.

Input and display of all ISO-8859-1 characters is supported.

You can have multiple X windows ("frames" in XEmacs terminology).

XEmacs has objects called "extents" and "faces", which are roughly
analogous to Epoch's "buttons," "zones," and "styles."  An extent is a
region of text (a start position and an end position) and a face is a
collection of textual attributes like fonts and colors.  Every extent
is displayed in some "face", so changing the properties of a face
immediately updates the display of all associated extents.  Faces can
be frame-local: you can have a region of text which displays with
completely different attributes when its buffer is viewed from a
different X window.

The display attributes of faces may be specified either in lisp or through
the X resource manager.

Pixmaps of arbitrary size can be embedded in a buffer.

Variable width fonts work.

The height of a line is the height of the tallest font on that line, instead
of all lines having the same height.

XEmacs uses the MIT "Xt" toolkit instead of raw Xlib calls, which
makes it be a more well-behaved X citizen (and also improves
portability).  A result of this is that it is possible to include
other Xt "Widgets" in the XEmacs window.  Also, XEmacs understands the
standard Xt command-line arguments.

XEmacs understands the X11 "Selection" mechanism; it's possible to define
and customize selection converter functions and new selection types from 
Emacs Lisp, without having to recompile XEmacs.

XEmacs provides support for ToolTalk on systems that have it.

XEmacs supports the Zmacs/Lispm style of region highlighting, where the
region between the point and mark is highlighted when in its "active" state.

XEmacs has a menubar, whose contents are customizable from emacs-lisp.
This menubar looks Motif-ish, but does not require Motif.  If you already
own Motif, however, you can configure XEmacs to use a *real* Motif menubar
instead.

XEmacs can ask questions using popup dialog boxes.  Any command executed from
a menu will ask yes/no questions with dialog boxes, while commands executed
via the keyboard will use the minibuffer.

XEmacs has vertical and horizontal scrollbars.

The initial load-path is computed at run-time, instead of at compile-time.
This means that if you move the XEmacs executable and associated directories
to somewhere else, you don't have to recompile anything.

You can specify what the title of the XEmacs windows and icons should be
with the variables `frame-title-format' and `frame-icon-title-format',
which have the same syntax as `mode-line-format'.

XEmacs now supports floating-point numbers.

XEmacs now knows about timers directly, instead of them being simulated by
a subprocess.

XEmacs understands truenames, and can be configured to notice when you are
visiting two names of the same file.  See the variables find-file-use-truenames
and find-file-compare-truenames.

If you're running on a machine with audio hardware, you can specify sound 
files for XEmacs to play instead of the default X beep.  See the documentation
of the function load-sound-file and the variable sound-alist.

An XEmacs frame can be placed within an "external client widget" managed by
another application.  This allows an application to use an XEmacs frame as its
text pane rather than the standard Text widget that is provided with Motif or
Athena.  XEmacs supports Motif applications, generic Xt (e.g. Athena)
applications, and raw Xlib applications.

Random changes to the emacs-lisp library: (some of this was not written by
us, but is included because it's free software and we think it's good stuff)

  - there is a new optimizing byte-compiler
  - there is a new abbrev-based mail-alias mechanism
  - the -*- line can contain local-variable settings
  - there is a new TAGS package
  - there is a new VI-emulation mode (viper)
  - there is a new implementation of Dired
  - there is a new implementation of Isearch
  - the VM package for reading mail is provided
  - the W3 package for browsing the World Wide Web hypertext information
    system is provided
  - the Hyperbole package, a programmable information management and
    hypertext system
  - the OO-Browser package, a multi-language object-oriented browser

There are many more specifics in the "Miscellaneous Changes" section, below.

The online Emacs Manual and Emacs-Lisp Manual are now both relatively
up-to-date.
