How to do live updating similar to Google Docs?

Question

I want to do something very similar to Google Doc\'s live updating - where all users can \"immediately\" see the actions of the other users in the doc.

To achieve this,

Answer 1

Another alternative is Orbited:

Orbited provides a pure JavaScript/HTML socket in the browser. It is a web router and firewall that allows you to integrate web applications with arbitrary back-end systems. You can implement any network protocol in the browser—without resorting to plugins.

Orbited is an HTTP daemon that is optimized for long-lasting comet connections. It is designed to be easily integrated with new and existing applications. Orbited allows you to write real-time web applications, such as a chat room or instant messaging client, without using any external plugins like Flash or Java.