The System.XML Assembly
XML support in .NET is provided by the classes in the System.XML namespace, or assembly. An assembly is a collection of related classes. In the case of System.XML, the classes are related by having to do with XML processing. The primary classes are as follows:
XmlTextReader: Provides forward-only, fast, noncached access to XML data
XmlValidatingReader: Used in conjunction with the XmlTextReader class to provide the capability for DTD, XDR, and XSD schema validation
XmlTextWriter: Permits generation of XML documents that conform to the W3C XML 1.0 specification
XmlNavigator: Supports evaluation of XPath expressions
Note that the Simple API for XML (SAX) is not supported in .NET. Similar functionality is provided by the XmlTextReader class, although there are significant differences, which are detailed later in the chapter.