What I need: a wiki that certain users can edit, with the option to embed multiple fora on certain pages, in which anyone can participate.

Does Wikia work for this? Is it the best option?

Please share far and wide. I need halps.

I am ok at programming, except my preferred languages are Python, Matlab, and R, so more or less useless here. HTML/CSS fine, of course.

eta: we have no money, so free options please. Ads are ok, though obviously not preferred.

eta2: see discussion here.