Push notifications for web applications can change the way web applications behave - Real time updates, chat services, stock alerts, etc. This was achieved earlier using XMPP, polling or long polling is sometimes too tedious, cumbersome or complicated for Do It Yourself approach.
Welcome Websockets, node.js, backbone.js and Redis pubsub for different ways to push notifications. This talk is about how we use all these in Ruby. I will also briefly touch upon Pusher.com - the online API that can do this on production sites without any setup required! A Live demo is in the offing!