On Friday 27 August 2010 at 20:31 Alexander Duscheleit wrote:
Yes, this is your right. Just as you can take some software released under "GPL2 or at your option, any later version" and redistribute it under GPL3 only. This is "your option". You do not have the pass the option on, since that doesn't form part of the copyleft.
Of course, someone else can redistribute the original under GPL2 only, GPL4 only, GPL2 "or later" or GPL3 "or later". That's their option :-)
That was my understanding, too. :-)
Excellent.
It gets more interesting, when I make changes to my redistributed software, though. If i understand correctly, if upstream is GPL2+ and my version is GLP3 only, I effectively either cut upstream out from my changes or force them to upgrade their version to GPL3 only (not even GPL3+).
Well, it's up to them what patches they include in the code they maintain, I suppose, so you can't force upstream to do anything. Many (most?) projects require you to licence your contributions under the same terms as the original if you want your patch considered (including any options), AFAIK. Doing otherwise, I suppose, would be considered a fork.
This looks to me, like I could violate the spirit of the GPL through the GPL itself.
I think the FSF are now encouraging people to contact contributing authors to obtain their agreement to relicense their work under GPL3, if they did not originally permit that "option". (Keeping the "or later" option is useful therefore, since it can help to avoid situations like the one you describe).
(Poaching in lawyers waters as a layman sure is fun :-D.)
Yeah - I have a good friend who does all this stuff for a living and it's fun hearing about various stories of the GPL's perception within businesses. Pete.