Just to be a stickler and clarify, Ajax is *not* another name for XMLHTTPRequest but a framework using XMLHTTPRequest among a handful of other technologies.
According to the auther credited with coining the term “Ajax”:
“Q. Is Ajax just another name for XMLHttpRequest?
A. No. XMLHttpRequest is only part of the Ajax equation. XMLHttpRequest is the technical component that makes the asynchronous server communication possible; Ajax is our name for the overall approach described in the article, which relies not only on XMLHttpRequest, but on CSS, DOM, and other technologies.”