This is the service pack 1 release of Microsoft? XML Core Services (MSXML) 4.0, formerly called the Microsoft XML Parser. This version has a number of improvements compared to MSXML 3.0:
Support of the World Wide Web (W3) Consortium final recommendation for XML Schema, with both DOM and SAX.
Substantially faster XSLT engine. Our tests show about x4, and for some scenarios x8, acceleration.
New and substantially faster SAX parser, which is also available in DOM with the NewParser property [use dom.setProperty("NewParser," true)].
Better support for sequential architectures and streamed XML processing based on SAX 2, including DOM-SAX integration and HTML generation.
Improved standards conformance and scalability. Specifically, the following old, non-conformant technologies have been removed: old XSL with XSLPattern; uuid namespaces for XDR; the proprietary XmlParser object; and the normalize-line-breaks property in SAX. Corresponding standard technologies (XSLT 1.0, XPath 1.0, and http-based namespaces for XDR and SAX2) have been available since MSXML 3.0.
True side-by-side functionality, which ensures that MSXML 4.0 can work without any collision with previous or future versions of MSXML. As a result, replace mode is removed completely. XmlInst.exe will not work with this release. Version-independent ProgIDs, such as DOMDocument, are also removed. You should use DOMDocument.4.0 to get MSXML 4.0 functionality.
A number of bug fixes.
MSXML 4.0 RTM is completely superceded by MSXML 4.0 SP1, which provides a number of additional bug fixes.