AJAX - What is that?

AJAX - Asynchronous JavaScript + XML (Wikipedia defintion) is a new term coined to represent an old technique. People have used the combination of JavaScript and XML for quite some time now, since late 90's.

The term itself has become quite popular in the web development arena. The growing popurality of AJAX became visible mainly with the advent of Google's GMail, Maps, Suggest.

Server-side UI frameworks like Sun's JavaServer Faces (JSF), a component framework, can have a AJAX based front-end (JSF-AJAX). They also have examples which are JSF based implementations of auto-complete, and progress bar.

Google Code has a open source project AJAX based XSLT called AjaXSLT.

"AJAXSLT is an implementation of XSL-T in JavaScript, intended for use in fat web pages, which are nowadays referred to as AJAX applications. Because XSL-T uses XPath, it is also an implementation of XPath that can be used independently of XSL-T."

OTOH, a section of the web developer community is moving away from client-side scripting (using JavaScript) to server-side frameworks like JSF, Tapestry.

Considering the amount of hardware resource available on the client-side, and the results seen from using GMail, I believe (in general) AJAX is the way to go...