XML Parser Version 2.6 and Version 3.0
The XML parser version 2.6 and version 3.0 extend the older version that came with Internet Explorer 5. The XML parser version 2.6 is a separate DLL (Msxml2.dll) that can be installed in addition to the original XML parser. Various options are available for running the two DLLs together, but those options are beyond the scope of this book. You can check the XML SDK 2.5 (which can be viewed on Microsoft's Web site) for more information about the DLLs. Version 3.0 of the parser is installed as a new DLL (Msxml3.dll) with new version-dependent CLSIDs and ProgIDs to protect those applications that use Msxml.dll or Msxml2.dll and allow you to choose the version of the parser to use in your code.
Version 2.6 comes with five additional XML document objects: XMLDOMDocument2, XMLDOMSchemaCache, XMLDOMSelection, XMLDOMXSLProcessor, and XMLDOMXSLTemplate. We will discuss the XMLDOMXSLTemplate and XMLDOMXSLProcessor objects in Chapter 12 when we discuss XSL. Version 3.0 doesn't add any new features to version 2.6. Thus, we'll have a detailed discussion about the XMLDOMDocument2, XMLDOMSchemaCache, and XMLDOMSelection objects in the following section.