I want to have several people colaborating on a game design spec. What I want is something where you can create sections and subsections, for the systems and subsystems, have user access levels to change each spec, change auditing, etc... This is sort of a software engineering question. I know there is a forum for that, but it's a bit dead.

you could look at some online mind mapping software like mindmeister (http://www.mindmeister.com). I think that Google Docs also allow for collaborative work on documents. You could also try a Wiki. There's about a dozen different types of wiki software out there. Or worse case, you could also build your own with PHP and a database (probably be very wiki-like).

Cheers,

Bob