Working with XML and Native Code
Microsoft XML Core Services (MSXML) is the native (Win32) API for high-performance XML-based applications that adhere to the XML 1.0 standard.
MSXML6 first shipped with SQL Server 2005, as a web release, and is included with Windows Vista and Windows 7. MSXML6 has enhancements for security, performance, stability, and improvements in XSD 1.0 & XML 1.0 conformance as well as support for x64 and Itanium architectures. It is recommended for applications that have Windows Vista or higher as minimum system requirements and those that can install MSXML6 using Windows Installer.