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Re: Using proprietary graphics in a free program


From: Tim Smith
Subject: Re: Using proprietary graphics in a free program
Date: Sun, 01 Mar 2009 13:28:09 -0800
User-agent: MT-NewsWatcher/3.5.3b2 (Intel Mac OS X)

In article <address@hidden>,
 Tord Romstad <address@hidden> wrote:
> I am Tord Romstad, author of Glaurung, one of the strongest GPLed
> chess programs. Recently, I ported my program to the Apple iPhone.  A
> couple of days ago, I was contacted by someone who wants to make a
> commercial chess program based on my program.  He understands that his
> derived program must also be available under the GPL, and intends to
> publish all changes he makes in my code, so everything is OK so far.
> 
> The problem is that he plans to hire a professional graphics designer
> to draw the piece images and some other graphics, and to keep these
> graphical image files proprietary.  He asks me whether the GPL allows
> this, and I honestly don't know myself.  Does anyone here know more
> about this?

Wait...you are the author?  Do you own the copyright on the program?
If so, you can let him use the code on whatever terms you want.  When 
you made it available under GPL, that did not preclude you also making 
it available on other terms (even closed source, proprietary terms).

GPL is a copyright license.  Here's how to think about copyright 
licensing.  Copyright law says that there are certain things that only 
you (the copyright owner) and people authorized by you are allowed to 
do.  The biggies here are copying, distributing, and making derivative 
works.

If someone wants to do one of those things legally, they have to have 
your permission in some form.  When you give person X permission in some 
form, that does not preclude you from giving person Y permission in some 
other form.  (Well, you could have made a contract with X in which you 
promised not to give anyone else permission in some other form, of 
course, but I doubt you did that!).

When you released the code under GPL, you were giving everyone 
permission if they followed the terms of the GPL.  You are still free to 
continue to grant people permission on other terms, including even 
giving them permission to make closed source, proprietary versions of 
your code (and you can do that yourself, of course, because you don't 
need permission).

The only limit on your ability to make your code available under non-GPL 
licenses is that if someone doesn't like the other licenses you might 
offer, they can fall back to the GPL version and use it under the terms 
of the GPL.

So, if you objected to what he wants to do, and were hoping to stop him, 
then the GPL would be very relevant here, because if GPL allowed 
non-free graphics in a free program, he'd be able to go ahead against 
your wishes.

However, it does not sound like you object.  In that case, the simplest 
thing to do is give him permission.  Give him an explicit license that 
says he may use the code under the terms of GPL, with the special 
exception that he may use proprietary graphics data files.  People on 
this group can probably help with the exact wording.

-- 
--Tim Smith


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