Does CC0 Allow Relicensing?
I came across a great piece of CC0-licensed art recently that I would like to use in an entirely-GPL project. As I understand it, CC0 allows relicensing, which means I could relicense the CC0 content as GPL without a problem, I believe. However, I'm not the best with licenses, and I can't seem to find anything in CC0 that explicity states that relicensing is allowed (although several areas of the legalese seem to imply that such a thing is possible and permissable), so I thought I'd ask for some opinions from others here before going ahead. :) I know for sure that CC0 is compatible with the GPL, but if possible I'd like to relicense it as GPL rather than having the two licenses exit side-by-side in the same project.
Also, apologies if this is the wrong place to post this; I seem to recall there was a "licensing" forum or something of that sort here once, but I can't find it now, so I must be mistaken...
As far as I know, CC0 allows any use. That should include relicensing.
I have an extention of the question. Is GPL and CC-BY-SA compatible? Can we relicense one with other? If not thats pretty big issue. Until now I always try not to use anything that is licensed SA or GPL (even LGPL).
cemkalyoncu,
They are "compatible" in that they are usually used side-by-side in games: GPL for the code, CC-BY-SA for the art. You cannot relicense one way or the other though.
For what it's worth: Creative Commons doesn't recommend using a CC license for code. I think Free Software Foundation doesn't recommend using GPL for art, but I can't find a handy link.
There is some dicussion on making CC-BY-SA 4.0 more compatible with GPL. You might hit up the Creative Commons mailing lists/forums/etc to chime in.
I know that CC is mostly art or literature while GPL is for code, however, there are lots of art resources that only allows GPL as license. That would make mixing art pain.
M'kay, thanks a lot Clint. :) I got the same impression, so unless someone says otherwise I'll assume it's okay to relicense CC0 assets.
Just in case though, I'll keep a list of whatever CC0 assets I end up using, that way I'll be able to remove them easily should any problems arise.
To the extend of my understanding CC-0 and CC-BY both allow relicensing (as least when including into a larger work !) CC-BY says the original author still has to be credited accordingly.
CC-BY-SA says it needs to be share alike, which is of course fullfilled by CC-BY-SA relicensing - I've got no certain opinion on relicensing as something else copyleft but it seems near valid.
As for GPL on the other hand: Once GPL, always GPL, don't relicense or reuse with other licenses besides those cases allowed by the FSF.
The GPL was never meant for sharing and using art - only it is that some GPL projects demand GPL art. (understatement)