This is a little narrower - but I'd be interested in suggestions for open source software useful for local online communities. People in my area use Facebook. Except that many (like me) just won't sign up for a FB account, and even those that do around here mostly loathe it.

I'd like to set something up but as this has just occurred to me I'm vague on specifics as yet. At a minimum I'd like easy-to-use community forums. Discourse is obviously a possibility.