Extensible Markup Languages (XML) history begins with the development of Standardised Generalised Markup Language (SGML) by Charles Goldfarb, along with Ed Mosher and Ray Lorie in the 1970s while working at IBM (Anderson, 2004). The purpose of SGML was to create vocabularies which could be used to mark up documents with structural tags.
XML is designed to store and transport data, it was created to provide an easy to use and store self describing data. XML became a W3C Recommendation on February 10, 1998. XML is not a replacement for HTML, it is designed to be self-descriptive. XML is designed to carry data, not to display data. XML tags are not predefined. You must define your own tags. XML is platform independent and language independent.