Extensible Markup Language (XML)
A document description language, primarily used to define Web pages and applications, that are compatible with Hypertext Markup Language (HTML) but provides more capabilities and flexibility. XML removes presentation constraints imposed by HTML and, in fact, does not necessarily require a Web browser. While both languages are platform independent, XML is also database and file format independent. To display an XML document (or run the XML application) the user's machine must be equipped with an XML parser.