XML

Extensible Markup Language. A meta-language, abbreviated version of SGML, used to specify other document types used on the Web.

Accepted as a format in 1998 to replace dependence on HTML extensions. MSIE 5.5 and Netscape 6 both support XML. XML enables designers to create their own customized tags to provide functionality not available with HTML.

For example, XML supports links that point to multiple documents, as opposed to HTML links, which can reference just one destination each.