We had a rather nice lecture about Model driven architecture by a guy from Model Labs. One thing that got me intrigued was the version control for models ( not to be confused with different models of version control) - or the lack of thereof. By version control for models he meant a way to version XML, EMF files which preserves their semantic.
So, I'm interested in what has been done so far on that field (he mentioned something about SVN and Moodle, though I could have misheard him). The Google search yielded nothing so I'm turning to the wisdom of the Stack Overflow.
I'm looking mostly for information in the form of books, articles, links.
I don't know of a VCS alone dedicated to Model, because Model-base design is often part of a all chain of documents that need to be kept in sync.
Namely (not an exhaustive list):
Plus, I never saw the GUI aspect fully solved in those tools (one model painstakingly organized a certain way might be versioned without layout information, and restored organized another way).
One tool I know of which covers all of those development processes is Modelio, which includes a "teamwork manager"
Another example (which I don't know as much about) would be metaCASE, which has an interesting paper "The Model Repository: More than just XML under version control", about DSM (Domain-Specific Modeling).
It does summarize the problem: