 <p>I spent a considerable amount of time looking into this. EventMachine needs to run as a thread in your rails install (unless you are using Thin,) and there are some special considerations for Passenger. I wrote our implementation up here: <a href="http://www.hiringthing.com/2011/11/04/eventmachine-with-rails.html">http://www.hiringthing.com/2011/11/04/eventmachine-with-rails.html</a></p>