Re: Is it possible to write GPL-Modules for closed-source Software?

[Alexander Terekhov]

Stay away from the [L]GPL (aka All Your Base Are Belong To GNU) and 
stick to something non-idiotic like the CPL or (its derivative with 
minor modification regarding patent retaliation) EPL.

http://www.eclipse.org/legal/eplfaq.php

----
21. If I write a module to add to a Program licensed under the EPL 
    and distribute the object code of the module along with the rest 
    of the Program, must I make the source code to my module 
    available in accordance with the terms of the EPL?

    No, as long as the module is not a derivative work of the 
    Program.

 [...]


26. Some free software communities say that linking to their code 
    automatically means that your program is a derivative work. Is 
    this the position of the Eclipse Foundation?

    No, the Eclipse Foundation interprets the term "derivative work" 
    in a way that is consistent with the definition in the U.S. 
    Copyright Act, as applicable to computer software. Therefore, 
    linking to Eclipse code might or might not create a derivative 
    work, depending on all of the other facts and circumstances.

27. I"m a programmer not a lawyer, can you give me a clear cut 
    example of when something is or is not a derivative work?

    If you have made a copy of existing Eclipse code and made a few 
    minor revisions to it, that is a derivative work. If you"ve 
    written your own Eclipse plug-in with 100% your own code to 
    implement functionality not currently in Eclipse, then it is not 
    a derivative work. Scenarios between those two extremes will 
    require you to seek the advice of your own legal counsel in 
    deciding whether your program constitutes a derivative work.
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#27's "scenarios between those two extremes" is about the AFC test.

http://digital-law-online.info/lpdi1.0/treatise22.html

Then go here:

http://www.innovationlaw.org/userfiles/page_attachments/Library/1/Heer_nonliteral_728806.pdf

Hth.

regards,
alexander.