XML (eXtensible Markup Language)
Subset of SGML, a Data Description Language (Metalanguage).
Allows fine-granularity markup of content and structure. Author can create their own elements (extensible).
Tags define the Structure of Document not Presentation Format.
Two types of valid XML: well-formed document structure without DTD and well-formed with validating DTD.
Displays natively only in IE 5.0 and Netscape 6.0.
Powers B2B, compatible with Relational DBs.