On 19/11/2007, Robert Rohde rarohde@gmail.com wrote:
On Nov 18, 2007 5:48 PM, Oldak Quill oldakquill@gmail.com wrote:
On 19/11/2007, Andrew Whitworth wknight8111@hotmail.com wrote:
There is a regular question on en.wikibooks that we have yet to find a
satisfactory answer on. I would like to know if some people here could give us some insight on the issue.
The question is whether an individual book, or even an individual page
can be cross-licensed under the GFDL and another license (such as CC-BY-SA-x.x). I know that individual contributors can release their content under a plethora of licensing schemes, but can we say that a single book is released under the GFDL and CC-BY-SA-2.5, for example? And even if we say that the book is licensed in that way, can we say that all future wikibooks editors MUST also agree to release their contributions to that book under that same licensing scheme?
The question arose earlier as to whether an individual book could be
entirely released into the PD, although we've already decided that this isn't really possible.
Would it be more reasonable to say that "XX version of this page, when
uploaded originally, was cross-licensed under GFDL and YY. Future revisions of this page are only GFDL, but it is possible to copy, distribute, and fork XX version under an alternate license as well, just not on this server."?
Derivative works must be licensed with both licenses if the original work is covered by both licenses. GFDL and CC-sa licenses require that derivative works are licensed with the same license (or a different version of the same license). Two licenses covering one work doesn't change the conditions of either license and isn't a reason to take the requirements of either license less seriously - both licenses must be carried across to derivative works.
This is false. It is a license not a contract. To create a legitimate derivative work, the author of the new version must have a legal right to do so. To accomplish this, he only needs to invoke one of the two licenses. Hence a derivative work need only be covered by one of the two prior licenses.
As a matter of policy, a wikiproject could hypothetically require that all pre-existing licenses be carried forward, but this would be a project issue, not a legal one.
Still thinking about our hypothetical GFDL and CC-by-sa dual-licensed document, even if the CC-by-sa license is used to "invoke" the right to a legitimate derivative work, this work will still have derived from a GFDL-licensed document and would also have to be licensed under the GFDL. At least, this is my impression of licensing and I may be wrong.
GFDL and CC licenses are independent of each other. One can't be chosen for a derivative work (and the other dismissed) if the original was licensed under both. Both licenses require that any derivative works must be licensed under the same or a similar license (GFDL and CC licenses are too dissimilar to be considered "similar licenses", and can't be substituted for each other).