StackExchange/campfire like chat app or server [closed]

Solution 1:

You may find that Campfire (campfirenow.com) is pretty solid. It has been recommended to me by colleagues, though I haven't used it myself yet. Its biggest draw-back is that it isn't free. Far from it.

In fact, StackOverflow Internet Services (your humble hosts) even used it internally before building their own:

http://blog.stackoverflow.com/2010/04/do-trilogy-sites-need-a-third-place/

(search for 'campfire')