A good framework that I have seen is Zephyr .
It is used with php and seems to be very easy to use.

You can get it from here http://zephyr-php.sourceforge.net

Hi

As i have been assigned for implementing Ajax in existing Complex JSF application my conclusion is to go for frameworks and tools if you are planning to build a fresh application.

otherwise just apply trics for incorporating ajax features.

the heart of this AJAX is to validate fields without refreshing the page..

else every thing thing is just javascript and CSS.

;-)

Shekhar

Prototype.JS Framework is available with detailed documentation its very easy to handle AJAX and JavaScript Introduce $ concept its very simple For Ajax specially u don't need to check cross broswer OPen Close and error handling through traditional AJAX.

There are so many - a good question as anyone who starts developing with ajax invariably has to look at some of the frameworks
http://ajaxpatterns.org/wiki/index.php?title AJAXFrameworks