Development of Creative Commons licenses

[Anthony <osm AT inbox.org>]

On Thu, Dec 29, 2011 at 9:28 PM, Arne Babenhauserheide <arne_bab AT web.de> 
wrote:
> Does usage under GPL actually create an additional restriction, if you
> consider the cc by-sa work be its own source?

My concern was with CC-BY-SA works which are not their own source,
which would be, I think, most of them.

You say "GPL has the same goal as cc by-sa".  I say no, it absolutely
does not.  Even the FSF says that its license recommendations "do not
concern artistic works that have an aesthetic (rather than functional
or educational) purpose".

It's not even clear how you *could* apply the GPL to certain CC-BY-SA
works.  What is the "source" for a photograph?  The preferred form for
making modifications would be the original RAW file.  But the GPL
requires that the distributed source "must be in a format that is
publicly documented (and with an implementation available to the
public in source code form)".  And RAW formats are typically
proprietary.