1.MSXML2.0
MSXML 2.0 provides support for XSL Patterns, the precursor to XPath 1.0. The notion of an XML addressing language was introduced into the original W3C XSL Working Drafts (http://www.w3.org/TR/1998/WD-xsl-19981216.html) and called XSL Patterns. MSXML 2.0 implements the XSL Patterns language as described in the original XSL specification with a few minor exceptions.
3.MSXML 4.0
Numerous features in this version provide XML Schema support. You can validate XML against XML schemas in both SAX and DOM using either an external schema cache or xsi:schemaLocation/xsi:noNamespaceSchemaLocation attributes. Although there is no XPath 2.0 yet, MSXML 4.0 provides extension functions, permitted by standards, to support handling XSD types in XPath and XSLT.