What Is MSXML?
Microsoft XML Core Services (MSXML) allows customers to build high-performance XML-based applications that provide a high degree of interoperability with other applications that adhere to the XML 1.0 standard.
Among the core services MSXML provides is developer support for the following:
The Document Object Model (DOM), a standard library of application programming interfaces (APIs) for accessing XML documents.
Helper APIs to assist with programming for XML namespace or the HyperText Transfer Protocol (HTTP) when it is used to send data directly between Web servers.
The XML Data Reduced schema definition language (XDR), which Microsoft introduced support for to assist with XML schema working needs while awaiting the now final W3C standard XML Schema Definition (XSD) language. Support for XDR is available in MSXML 3.0 through MSXML 5.0. MSXML 6.0 does not support XDR.
The Simple API for XML (SAX), a programmatic alternative to DOM-based processing.
The Schema Object Model (SOM), an additional set of APIs for accessing XML Schema documents programmatically that was introduced in MSXML 4.0 and later.
XML Digital Signatures support, which provides the ability to sign and verify XML document data through digital encryption. This support is only available in MSXML 5.0 for Microsoft Office Applications. It was removed in MSXML 6.0.