Extensible Markup Language is mostly used for the data-exchange on the Web and was orginally designed for electrinic publishing. It defines a set of rules for encoding documents in a simple, very flexible text format which is both human-readable and machine-readable. It is defined by the W3C's XML 1.0 Specification1), derived from SGML (ISO 8879) and other open standards.2)
XML was developed by an XML Working Group of the World Wide Web Consortium (W3C) in 1996. It was chaired by Jon Bosak of Sun Microsystems with the active participation of an XML Special Interest Group (previously known as the SGML Working Group) also organized by the W3C. The membership of the XML Working Group is given in an appendix. Dan Connolly served as the Working Group's contact with the W3C.3)
The design goals for XML are:
For an overview, here are some of the more important constructs used in XML.
Tags start with < and end with >, appearing in 3 shapes: