I\'m thinking about how limiting it is for AJAX apps to have to poll for updates, when what would be ideal is for javascript to be able to set up a real two way connection t
Here is an implementation with a similar approach:
It uses a Java Applet and bridges its API to JavaScript, interesting...
And here another one:
This one is a wrapper of the Actionscript 3 Socket API, bridged to JavaScript...
jSocket and Stream are two options that utilize Flash's built-in XML sockets, though neither appears to be production-ready. I'd lean towards using a Flash-based solution rather than Java, as browser penetration is higher and generally offers a better user experience (load times & stability).
WebSockets is designed to solve this problem.
You can use node.js framework's socket.io package which can can be installed via npm (A node package manager).
More detailed usage.