A language used by Web developers and designers for creating declarative markup languages like Hypertext Markup Language (HTML), only more flexible in that documents written in XML can be shared across different information systems, particularly the Internet, and can adapt to different presentation style sheets and applications. A condensed form of Standard Generalized Markup Language (SGML), XML is published and maintained by the World Wide Web Consortium (W3C). See also W3C and Web. G.992.3, G.992.4 (2002) Max RateUpstreamMax RateDownstreamITU-T Standard