New Apple Article--"Dynamic HTML and XML: The XMLHttpRequest Object."

As deployment of XML data and web services becomes more widespread, you may occasionally find it convenient to connect an HTML presentation directly to XML data for interim updates without reloading the page. Thanks to the little-known XMLHttpRequest object, an increasing range of web clients can retrieve and submit XML data directly, all in the background. Safari version 1.2 supports the XMLHttpRequest object. Read this article to learn how to fetch, store and access XML data on a server for use as web content.