Best free Wiki and forum hosting?

I'm looking for a way to host both a forum and a wiki from a single domain.

Who can provide both these services?

Is there a way to use some sort of free-but-good domain service to use the best free forum providers and the best free wiki provider while keeping it all `under one roof` aka under the same free domain?


How do I do that?

PMWIKI if you don't have high demand, though the forum choices are a bit sparse....We use ours for a tech site at our organization and it works perfectly.