AJAX (Asynchronous JavaScript And XML) is the name for a relatively new breed of web applications, which behave more like computer-installed applications. The most well known examples are GMail and Google Maps, but now there are many more.
A Venture Forth came up with a top 10 list of AJAX applications (EDIT: a follow-up article has been posted, too). Some of the examples are really cool. I especially liked the Kiko calendar (try the demo if you’re not interested in registering).
(via Download Squad)