...rather than use a CMS at all, you might be better off using something like Git - perhaps with a service like https://github.com or http://gitorious.org/ to host your repos, as they'll provide wikis and some basic discussion/community features with them.
Otherwise, perhaps a Git repo combined with a separate-ish main community powered by a CMS or even simply a forum (such as Simple Machines Forum or FluxBB), using one side for the community aspect and the other for development.
For more info about Git, check: http://git-scm.com/
You could also use Subversion or a similar version control system - Git just happens to be very popular currently.
--
On the flipside, if you want to run everything through a CMS, you're likely to have to heavily customize that CMS (depending on your level of experience, you may need to hire someone or a company to do so for you - perhaps a paid CMS or a free one whose developers are available to hire to customize it). It's doable, but I don't know of any (and doubt there really are any) out-of-the-box ways to do it.
You could also always just start a forum/project on http://www.moddb.com/ for it and run it there. Not quite as custom or in your own hands, but very simple and giving you access to a large community and set of tools right off the bat.
--
As for ModDB.com itself, in case you were curious: it runs on the DesuraNET Web Engine - http://trac.moddb.com/web - which is made by, you guessed it, DesuraNET, parent company of Desura, ModDB, and indieDB. As far as I can tell, they don't release their project (though you can learn a bit about it from it's trac page - hit that link) for public use.
-Patrick J. B. Simmons | @hobbramble
"If I could give you one piece of advice to remember for the rest of your life, it would be this: when Patrick tells you to do something, do the opposite." - Nolan Ladewski