"ph" == perl@hush.ai writes:
ph> I would think that we would be able to use work originally ph> licensed under the cc license on wikipedia even if we ph> relicense it under the GFDL. There is nothing in the cc ph> license that says we can't.
(I am not a lawyer; this is not legal advice.)
Hurgh. Well, that depends on the CC license you're talking about. There are 11 core licenses, and several additional ones.
Any Creative Commons license that has the ShareAlike license element has this clause in the license:
"You may distribute, publicly display, publicly perform, or publicly digitally perform a Derivative Work only under the terms of this License, [...] You may not offer or impose any terms on the Derivative Works that alter or restrict the terms of this License or the recipients' exercise of the rights granted hereunder, [...]"
In other words, you're not allowed to add additional licenses, or change the license. That's the essence of copyleft. You use _exactly_ the same license for derived works. Same thing for the GFDL, btw:
"You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License,"
Non-copyleft licenses don't have that kind of restriction. But most of the CC licenses that aren't copyleft have other provisions (NoDerivatives, NonCommercial) that make them unsuitable for incorporating into GFDL material. Derivatives of works licensed under the Attribution license (just requires attribution) could probably be licensed under the GFDL.
The original creator can offer a work under any license or licenses they want. Dual licenses would probably work.
ph> I think some wikipedians even use photos that are licensed ph> under the cc.
This all depends on what the "Document" is in the GFDL (called the "Work" in CC licenses). It's not stated on the copyrights page:
http://en.wikipedia.org/wiki/Wikipedia:Copyrights
...or anywhere else that I know of what the Document is, but I think we tend to treat them as individual images and individual articles, _separately_. So it's OK to put images and articles together that have different licenses. Taking elements of a Creative Commons Attribution-ShareAlike-licensed image, say, and making a GFDL'd image, would not be OK: it'd be making a Derivative Work, which has to be under exactly the by-sa.
Needless to say, this is hairy stuff. Why not avoid it wherever possible?
~ESP