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Subject: Re: Usage of egtb.cpp in GPL software (Amy, ExChess, ...)

Author: Dann Corbit

Date: 17:07:46 12/05/00

Go up one level in this thread


On December 05, 2000 at 14:03:24, Gian-Carlo Pascutto wrote:

>On December 05, 2000 at 13:20:05, Dan Andersson wrote:
>
>>I would say that its a problem for Amy and ExChess et al, not to Nalimov but >its easy to work around The authors ask Eugene for permission to use the code
>>and point out what parts if any that are not GPL.
>
>For Eugene, there is indeed no problem at all. For Amy and ExChess I
>think things are not so easy.
>
>The GPL says:
>
>These requirements apply to the modified work as a whole.  If
>identifiable sections of that work are not derived from the Program,
>and can be reasonably considered independent and separate works in
>themselves, then this License, and its terms, do not apply to those
>sections when you distribute them as separate works.
>
>-> So far so good.
>
>But when you distribute the same sections as part of a whole which is a work
>based on the Program, the distribution of the whole must be on the terms of
>this License, whose permissions for other licensees extend to the
>entire whole, and thus to each and every part regardless of who wrote it.
>
>I think this basically means that if Amy and ExChess want to continue
>using the Nalimov code they will have to get Eugene to grant a special
>permission...that effectively puts that code under GPL, or stop
>distributing their programs under GPL. Using GPL code and non-free code
>together is a very complex issue. See the whole KDE/Qt drama. I am not
>suprised running into this with the EGTB code, since it was a piece of
>code with shaky copyrights that is used in GPL software.

This is [of course] the "GPL Virus" theory.  Of course, your *own* GPL software
can have more relaxed constraints like those in LGPL.  Personally, I greatly
prefer public licensing like the Berkeley license style or the ACE license
style.  I have also made contributions to Snippets, which is public domain.

>I thought about making my own (GPL) tablebase generator, that would be
>usable for chess variants like suicide also. However, making such a thing
>efficient and generating all databases is another matter. Nalimov format
>is very good.
>
>>Easy Copyrigth link:
>>
>>http://www.templetons.com/brad/copymyths.html
>
>It's a nice link but it doesn't help much trying to understand difficult
>issues like using non-GPL code in a GPL program.

Yet another problem with that format (IMO).  But I don't much like it.



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