Thanks to Ross Mason for this spot: http://rossmason.blogspot.com/2008/05/facebook-chat-uses-erlang.html If you click through from his blog, there is a pretty interesting summary of how FB do chat. alexis -- Alexis Richardson +44 20 7617 7339 (UK) +44 77 9865 2911 (cell) +1 650 206 2517 (US)