I\'m going to develop a collaborative site, and one of the features will be collaborative editing with realtime changes. i.e. when two or more users are editing the same doc, th
One thing worth mentioning is the production story. EM, like most Rack stuff, has plenty of testing and monitoring tools available that are well tested, whereas Node.js falls well short in this respect.
At the time of writing, it seems almost impossible to get clear metrics from Node to answer questions like 'Do I need to scale'. There are options starting to form out there from the likes of Joyent, and always the roll-your-own argument, but nothing anywhere near tools such as NewRelic.
Node.js is very good from a performance / configurability point of view, but personally I wouldn't host it in production just yet.