Extensible Hypertext Markup Language; a reformulation of HTML as an XML application.
XML (Extensible Markup Language) is a set of rules for encoding documents electronically.
XML’s design goals emphasize simplicity, generality, and usability over the Internet. It is a textual data format, with strong support via Unicode for the languages of the world. Although XML’s design focuses on documents, it is widely used for the representation of arbitrary data structures, for example in web services.