I\'m questioning myself why should I use combination of Node.js + CouchDB versus CouchDB standalone approach. What are the benefits of getting Node.js into the game? Any comment
couch on its own (couchapp):
apparently, couchdb can do a lot of cool offline stuff - e.g. user goes offline, carries on, and syncs on reconnect. i haven't had a reason to use this feature yet, but it makes a lot of sense for mobile phone webapps and I'm looking forward to having a go:
http://googlecode.blogspot.co.uk/2009/09/chris-anderson-couchdb-relaxing-offline.html
node.js is designed to run server-side, so its not a great fit for this use case, except in the architecture described in nick perkins's answer.
node + couch
if you're doing anything more than a simple js app, node has a vibrant community with all kinds of libraries and packages to do pretty much anything.
this approach also allows you to hide couch behind a firewall, and only let people speak to it through your node app.