MOSS 2007 and XML

XML is at the core of Office system 2007 spanning client and server technologies. the 2007 Office system introduces a new Open XML format that allows much easier programmatic access to Office files. Microsoft Office InfoPath uses XML for gathering information, with the flexibility to incorporate data from many sources in a single form. On the server side, XML surfaces in a variety of ways allowing enterprises to style the content in the format they want by using Extensible Stylesheet Language Transformations (XSLT). (source: Microsoft whitepaper on 2007 Office, Dec 2006)