Prototype framework enables you to deal with Ajax in a very easy way. It simplifies the way of using Javascript and deals in a smart way with JavaScript code returned from a server and provides helper classes for polling. And also, it is cross-browser compatible.

The biggest part of the Prototype framework are its DOM extensions. Prototype adds many convenience methods to elements returned by the $() function: for instance, you can write $('editForm').addClassName('active').show() to get the element with the ID ‘editForm‘, add a class name to it and show it (if it was previously hidden).

This framework can save you more than 50% on coding javascript and developing an ajax driven with large amount of DOM manipulations web site. If you have not tried it, please have a look. A well-defined framework is needed for developing a professional web application.

Requirements: Any Browsers
Demo: http://www.prototypejs.org/api
License: MIT License