Currently there is a [plethora of websocket libraries](http://npmjs.org/keyword/websocket) for node.js, the most popular seem to be:

* <https://github.com/Worlize/WebSocket-Node>
* <https://github.com/einaros/ws>
* <https://github.com/LearnBoost/engine.io>
* <https://github.com/learnboost/socket.io>
* <https://github.com/sockjs>

However I can't find any solid concrete comparisons between any of them...
Apparently Socket.io was awesome, but has become quite dated and has failing builds. Both ws and websocket-node claim they are the fastest. And engine.io seems new, but a lot heavier than the lighter aletarntives.

It would be amazing if we or someone could put together an answer that serves as a guide on which socket library to use and when, as well as a comparison between them.