Subj : Re: Copyright and addons or comercial GUI for a GPL software
To   : comp.programming
From : aslanski2002
Date : Thu Aug 11 2005 05:41 am


Giannis Papadopoulos yazdi:
> aslanski2002@yahoo.com wrote:
> > Jonathan Bartlett yazdi:
> >
> >>>Are there any restrictions in using GPL code in comercial applicatins?
> >>
> >>Yes.
> >>
> >>
> >>>I have seen the Linux Kernel used on a lot of appliances.
> >>
> >>That's because the kernel is not linked to the program.
> >>
> >>
> >>>My intention as I mentioned in an earlier  thread is to design a good
> >>>interface for some GPL applications and to sell this interface.
> >>
> >>Selling is not against the GPL.  Selling under non-GPL licenses is.
> >>
> >>
> >>>I will
> >>>not charge for the application itself but I think it is fair to charge
> >>>for the interface. The design requires a lot of work for design and
> >>>implementation.
> >>
> >>The amount of work is irrelevant.  What is relevant is whether or not
> >>your work is considered a derivative work.
> >>
> >>If you link to libraries, that is usually considered a derivative work.
> >>  Static linking definitely is, dynamic linking using headers supplied
> >>under the GPL also is.  I do not know of the rules for dynamic linking
> >>without the GPL headers.  However, if you are not linking to the GPL
> >>work, but merely using it as a separate application, there is no
> >>problem.  In fact, I know Mathematica does this.  If you look on the CD
> >>they distribute you will see a source file containing a GPL application
> >>which they use as a separate, unlinked application but is distributed
> >>with Mathematica.
> >>
> >>As for LGPL libraries, there are other rules.  With those, you are
> >>allowed to freely dynamically link.  For static linking, there are more
> >>rules, but basically you have to provide the unlinked versions of both
> >>your code and the libraries, so the user can upgrade the library and
> >>relink if he wishes.
> >>
> >
> > I have questions here:
> > I have an application *A* which uses a DLL *D1* with (L)GPL code in it
> > and another *D2* which has no (L)GPL code. *A* still can work if you
> > delete *D1* (though not fully functional). And *A* has no (L)GPL code
> > in it.
> > - Do I still have to provide sources for *A* ?
> > - I don't think I have to provide the sources of *D2*, do I?
> >
> >
> >>Jon
> >>----
> >>Learn to program using Linux assembly language
> >>http://www.cafeshops.com/bartlettpublish.8640017
> >
> >
>
> If D1 is GPL, then yes you have to provide A sourcecode. If it is LGPL
> you don't have.
>
What if I provide *A* and *D1* as proprietary and some knowledge of how
to create a plug-in for *A*. And some user creates a plug-in for *A* (
call it *D2*) using some GPL code, isn't this the case where I have to
provide source of *A*? I can't stop a user doing it!

> Your best option is to create a new D1 that is yours (proprietary)...
> Or open-source A
>
> --
> one's freedom stops where other's begin
>
> Giannis Papadopoulos
> http://dop.users.uth.gr/
> University of Thessaly
> Computer & Communications Engineering dept.

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