<quote who="Robert Rohde" date="Sat, Dec 01, 2007 at 03:43:14PM -0800">
On Dec 1, 2007 3:32 PM, Erik Moeller erik@wikimedia.org wrote:
On 12/2/07, David Gerard dgerard@gmail.com wrote:
Greg will of course correct me if I'm wrong - but I suspect the problem is that lots of people want CC-by-sa because it's easier to reuse stuff ... but that GFDL makes it hard to reuse stuff is considered a *feature* by many, e.g. photographers who license work as GFDL but also sell it privately. That is: the thing that makes GFDL a pain in the backside for a wiki is precisely why they like it, and they want it to stay a pain in the backside for that reason.
Worst possible reason to like a license, ever. :-)
Let's make a strong copyleft license that appeals to photographers.
In my opinion, that is only possible if the copyleft provisions unambiguously transfer to text written to accompany the image. Anything less, is little better than CC-BY. Most people that use photographs do so for the purposes of illustration rather than for the purposes of making derivative images. Hence copyleft provisions that apply only derivative images, and not to the text being illustrated, are intrinsically weak and of little impact.
My understanding, having talked to several lawyers about this issue, is that this "difference" hangs on interpretation of case law about what constitutes a derivative work. The answer to the question is incredibly ambiguous and jurisdiction specific.
It is, in fact, a matter of extra-license legal definitions and not of license or what CC/FSF/SFLC thinks. The FSF and CC each have positions on this that, in various jurisdictions, are each contradicted by existing case-law. Neither license says anything in the text of the license and neither plans to.
If the author of a work under BY-SA subscribes to the more expansive definition of derivative work and litigates in a jurisdiction that is friendly to it, they'll probably have luck. If they use the GFDL and are in a jurisdiction that has precedent saying otherwise, they won't.
There is, as I have come to understand, no difference between the licenses in this regard that would prevent compatibility.
Regards, Mako