SAX Win32 AppWizard Creates a Visual C++ SAX Application

Instead of using the Document Object Model (DOM), you can use the Simple API for XML (SAX) to provide a lower-level API to parse XML data that can result in a much greater performance gain under certain scenarios. For example, a messaging scenario where you preprocess and reroute XML documents to other servers.

http://support.microsoft.com/default.aspx?scid=kb;EN-US;q276505