Toby wrote:

But the burden of proof lies with /you/, who insist on fixing everything in the GNU FDL to begin with.

? No. All Wikimedia projects are under the GNU FDL and yet you want to make an exception here. I fail to see how the burden of proof is on me.

No exchange can be hindered by a disjunctive license, because a GNU-only project can always borrow from a disjunctive one, and a disjunctive project can become GNU-only if it decides to borrow from a GNU-only project.

What do you mean exactly by a "disjunctive project"? And your use of the word "project" is very confusing here - Wikibooks is the project and the individual books are more akin to WikiProjects. In one sense you use the term "disjunctive" to mean that each book decides what license to use (GFDL or CCSA) and then you state that a book in in one license can barrow from a book under a disjunctive license.

Don't you mean to say "dual license" for the latter example? That still doesn't really make sense because a dual licensed work has a net flow of text copied out instead of copied in for this simple reason; all text that goes into a dual licensed work /has/ to be dual licensed. So even though a book may be under a GFDL/CCSA dual license it /cannot/ accept GFDL only or CCSA only text. Why would such a project choose that license combination in the first place?

If there were no Wikipedia or any source like it, would you still want to start Wikipedia on the GNU FDL alone?

That's rather hypothetical but without thinking it through too much I would have chosen an in-house license like Jimbo suggests (allowing our work to be licensed under one of several of a short list of outside licenses). But that would only solve the issue about our text being re-used elsewhere.

Once something gets placed under one of those licenses and mixed with other text that is solely under that license, then we are faced with the very odd situation where we cannot use the resulting work (unless the owner of the derivative work agrees to license their GFDL only part of their work, for example, under our in house license).

OK, I'm getting a headache - this is all very complicated and the more I think about it the more I'm convinced that since that we should not change things - we are stuck with the GNU FDL and should work with the big boys on getting them to play nicely together.

So why do you want to saddle my project with the GNU licence, when next year I may find a CC SA textbook to join forces with?

Vaporware. Come back when you actually find a textbook you want to use that is under a GFDL incompatible license and then we can consider the situation.

And you could always ask the copyright holder about a change in license. We have already been successful in getting many people to re-license external /proprietary/ text under the GFDL. So I wouldn't be surprised at all if a person with a CCSA book would agree to license their work to us under the GNU FDL. Furthermore we have already uncovered a great many GFDL books already on the Internet. Again - where are these other resources?

What you propose to do is add a great deal of needless complexity to solve a problem that does not exist. If and when we come across a huge CCSA (or similar) resource then we can think about having a disjoint system (only our efforts to ask the copyright holders about giving us a GFDL license of their work fail). But for now all this is just a needless distraction.

--- Daniel Mayer (aka mav)