AJAX isn't something that's "new" or "around". It's not a language and it's not a technology. It's more of a methodology.

AJAX (Asynchronous Javascript and XML) is used to describe anything that implements Javascript's XMLHTTP Request Object (As Koobi said).

There has been a lot of confusion between people new to AJAX in thinking it's a language or a new technology. It's simply just people plugging 2 and 2 together

Regards,
Patrick