AJAX seems to be the new "buzzword of the day". In short, AJAX stands for "Asynchronous JavaScript And XML", an acronym coined by Jesse Garrett recently. The basic idea is very nice - you can actually perform client-side programming directly in the DHTML code, in the embedded JavaScript. And, while the DHTML page interacts with the user, it talks asynchronously in the background with the server through a variety of methods, notably by sending/receiving XML fragments.

This acronym is mostly used today in the context of Google Maps. I admit that it looks pretty cool - I even posted a while back a technical article about how it uses the AJAX concepts here.

But is this AJAX concept something new? Well, it quickly turns out that it's not. Although we don't see it all over the place, people already used this idea pretty heavily in the past few years. I would pick a notable example: Outlook Web Access.

OWA has been out there for years, since the good old days of Microsoft Exchange 5.5. I was always amazed by this application, especially in the most recent versions, by its ability to mimic pretty closely the look-and-feel of the Outlook client. The latest incarnation of OWA has two flavors. The rich OWA uses a combination of several technologies at the browser side (JavaScript, WebDAV, XML, XSLT, etc) to create a pretty interactive application. The reach version uses very few browser features, and it even works with IE 4.02 or earlier (although I am not sure if anybody is using that browser version :-)

[update: more AJAX-related posts from Microsofties: here and here]