Comparing comet performance between node and ringo should be interesting. Ringo uses jetty/cometd, so it should scale pretty decently as well. My guess is that node will use less memory per connection (and thus allow more simultanous connections), while ringo/jetty should have better latency. This is also what this benchmark suggests: http://praxx.is/post/486034949/comet-with-bayeux-node-js-vs-...