"You really can't do any significant programming today without running across XML. Whether you're a Web page designer considering the move to XHTML, a Web programmer working with JavaScript, a server-side programmer using deployment descriptors and data binding, or a back-end developer investigating XML-based databases, the extensible markup language is everywhere. It's no surprise, then, that XML is considered one of the core technologies that underlies Ajax.
"However, this opinion reflects the poor choice of names for the core object used in Ajax applications--XMLHttpRequest--more than it does technical reality. In other words, most people think XML is a core part of Ajax because they assume that the XMLHttpRequest object actually uses XML all the time. But that's not the case, and the reasons why are the subject of the first part of this article. In fact, you'll see that in most Ajax applications, XML rarely makes an appearance at all..."
