Very clear with the words, AJAX is not a programming language, its simple a development technique for creating interactive web application.
The AJAX technique makes web pages more responsive by exchanging data with a server behind the scenes, instead of reloading an entire web page each time a user makes a change.
With AJAX, web applications can be faster, more interactive, and more user friendly.
Ya, while talking of AJAX how come someone leave without taking the name of Google which makes the AJAX megahit. Google hottest applications are using AJAX like Google Gmail, Google Map, Google Chart. Not only this how come others be so slow in race. Flickr whole development in AJAX.
But the real problem comes when techology grows and what is with AJAX ?
Google don't want to continue this hot technology with Java Script. Google developers itself had to spend more than a month to run Google Map in Apple's Safari.
People look to Google as an Ajax community leader because of its success with Maps, Calendar and Gmail, so anything they do will warrant a lot of attention and hopefully encourage more Ajax development.
Some patches are still left to fix like to run it on native Mac OS. But we all will see GWT soon in market. Lets see , Is this technology is going to make a difference !