XML

XML, or Extensible Markup Language, is a markup language that you can use to create your own tags. It was created by the World Wide Web Consortium (W3C) to overcome the limitations of HTML, the Hypertext Markup Language that is the basis for all Web pages. Like HTML, XML is based on SGML -- Standard Generalized Markup Language. Although SGML has been used in the publishing industry for decades, its perceived complexity intimidated many people that otherwise might have used it (SGML also stands for "Sounds great, maybe later"). XML was designed with the Web
in mind.

XML is an open, text-based markup language that provides structural and semantic information to data. This "data about data," or metadata, provides additional meaning and context to the application using the data and allows for a new level of management and manipulation of Web-based information. XML, a subset of the popular Standard Generalized Markup Language (SGML), has been optimized for the Web. This helps make XML a powerful, standards-based complement to HTML that could be as important to the future of information delivery on the Web as HTML was to its beginning.

XML is intended to be used by content creators as well as by programmers. Since XML is text-based, it can be read and worked with easily in relatively nontechnical situations, but its ability to organize, describe, and structure data also makes it ideal for use in highly technical applications. XML thus provides common ground for creating structured data and making it available for manipulation and display.