Microsoft Knowledge Base Article 914783 contains the following summary:
This article describes an update package that provides the XmlLite low-level XML parser. This update installs XmlLite on computers that are running Windows Server 2003 with Service Pack 1 or the x64-based version of Windows XP.
XmlLite is a low-level XML parser that you can use to build powerful XML-based applications. Additionally, you can use XmlLite to interact with applications that use the XML 1.0 format.
For more information about XmlLite, visit the following Microsoft Web site:
For more information about the XmlLite update package for computers that are running 32-bit versions of Windows XP, click the following article number to view the article in the Microsoft Knowledge Base:
915865 The XmlLite update package is available for 32-bit versions of Windows XP with Service Pack 2