NowJS is a NodeJS module. The client javascript

NowJS is a NodeJS module. The client javascript (now.js) is served by the NowJS server. NowJS creates a magic namespace “now”, accessible by server and client. Functions and variables added to now are automatically synced, in real-time.
You can call easily client functions from the server and server functions from the client. That means you can push to the client simply by calling a client-side Javascript function on the server. Communication is achieved using Socket.io
NowJS v0.2 is supported in Chrome, Opera, Safari, Firefox, and IE9. Support for older version of IE is coming.

Requirements: Node.js and Socket.io
Demo: http://nowjs.com/
License: License Free