Professional Ajax, 2nd Edition

6.1. XML Support in Browsers

Many web browsers are available today, but few have complete support for XML and its related technologies. Internet Explorer (IE) and Mozilla Firefox lead the pack in support, followed closely by Opera (as of version 9). Apple's Safari trails significantly behind, supporting only rudimentary XML features. Despite these differences in support, all browsers implement basic XML functionality; therefore, this section covers all four major browsers.

6.1.1. XML DOM in IE

When Microsoft added XML support to IE 5.0, they did so by incorporating the MSXML ActiveX library, a component originally written to parse Active Channels in IE 4.0. This initial version wasn't intended for public use, but developers discovered the component and began using it. Microsoft responded with a fully upgraded version of MSXML, which was included in IE 4.01.

MSXML was primarily an IE-only component until 2001 when Microsoft released MSXML 3.0, a separate distribution available through the company's web site. Later that year, version 4.0 was released and MSXML was renamed Microsoft XML Core Services Component. Since its inception, MSXML has gone from a basic, non-validating XML parser to a full-featured component that can validate XML documents, perform XSL transformations, support namespace usage, the Simple API for XML (SAX), and the W3C XPath and XML Schema standards, all while improving performance with each new version.

6.1.1.1. Creating an XML DOM Object

To facilitate ActiveX ...