Review on SocketCluster by David Stewart

It's very easy to use, doesn't require much configuration or setup beyond what you'd need with any other node server library (we're using it in combination w/ socketio). The built-in clustering functionality works great! If there were some way of connecting directly via URL instead I would be even happier; but that may not always make sense depending upon user needs / situation at hand so we'll stick within their API where possible :) Great option if your backend service requires realtime communication between different parts - our clients are building mobile apps which have chat features & such like this could take advantage without having additional infrastructure set up elsewhere.