[ComNik]

Would you pay for that? In something like a GitHub Enterprise setting, closed source but self-hosted?

Something like FB-Groups for organizations of all kind fell out as a byproduct of our startup and we are toying with the idea of trying to sell that part in isolation. Basically you get your own, hosted / self-hosted FB-Groups, plus a bit more flexibility regarding permissions and group management. For example you could introduce someone external into a sub-topic in one of your groups, without exposing him to the rest of the group (not sure if that is possible with FB groups).

[Edit: Grammar]

[kyllo]

I think that would be basically competing with Yammer, which is owned by Microsoft.