Subj : Re: Copyright and addons or comercial GUI for a GPL software
To   : comp.programming
From : Giannis Papadopoulos
Date : Thu Aug 11 2005 02:43 pm

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.

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.

.