[cc-licenses] Most important feature: GPL-compatibility
bydosa at davidchart.com
Fri Jan 6 22:05:21 EST 2012
I don't think allowing conversion to the GPL is a good idea, and I don't think that GPL compatibility is possible.
On the philosophical point, if the GPL can already be used for any creative works, then there is no need for a CC license doing the same thing. The claim that a truly free work must come with the source is thus not relevant to the question of how the CC licenses should be revised. The argument must be that it is, in general terms, a good idea for CC-BY-SA works to be also licensable under the GPL.
I think it would be a bad idea to allow works currently licensed under CC-BY-SA to be relicensed under the GPL. The authors releasing those works could have released them under the GPL, but chose not to. Having CC change that decision for them without consultation would be politically dangerous, I fear; a lot of people would start suggesting that you can't trust the CC not to issue version 5.0 with a clause saying "Google can use this stuff however it likes under any licence". (Google promises not be evil, so that's OK, right?)
More practically, I don't think it's actually *possible* to distribute a wide range of BY-SA works under the GPL. 3.0 defines source code, and clause 6 says that when you convey an object form (not the source), you must convey machine-readable Corresponding Source. For a fair number of works that BY-SA might be used for, the preferred form for modifications is not machine-readable. The GPL simply doesn't apply. The source must also be in a publicly-documented format with an available source code implementation. Even for electronic works, this is often not the case; artists who work in Photoshop, for example, cannot provide the preferred form for modifications in such a format, because the preferred form for modifications is a Photoshop file.
I also strongly doubt that you can get away with saying "whatever we have is the source code"; the language looks designed to exclude the binary blobs that come with some hardware. In that case, a conversion clause is meaningless; you cannot distribute under the terms of the GPL, because you cannot hold to those terms. (A conversion clause would provide no leverage to get the original creator to provide the source; if someone holds copyright, says that they are releasing something under the GPL, but fails to provide source, they have merely failed to release something under the GPL. Barring other contracts, they have no obligation to succeed.)
I can see that it is inconvenient for video games, and that the original intent of the artists almost certainly was for the images to be usable in any video game, but I don't think that problem should be solved by changing the license. Instead, you should get the works relicensed (should be no problem if the artists really did mean that), or rewrite the code so that you can use artwork released under a different license, even a non-free one. I'm well aware that neither of those, particularly the second, is a trivial task...
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