HyperText Markup Language is a markup language that web browsers use to interpret and compose text, images and other material into visual or audible web pages. Default characteristics for every item of HTML markup are defined in the browser, and these characteristics can be altered or enhanced by the web page designer's additional use of CSS. Many of the text elements are found in the 1988 ISO technical report TR 9537 Techniques for using SGML, which in turn covers the features of early text formatting languages such as that used by the RUNOFF command developed in the early 1960s for the CTSS (Compatible Time-Sharing System) operating system: these formatting commands were derived from the commands used by typesetters to manually format documents. However, the SGML concept of generalized markup is based on elements (nested annotated ranges with attributes) rather than merely print effects, with also the separation of structure and markup; HTML has been progressively moved in this direction with CSS.
November 1990 - HTML was published
November 1995 - HTML 2.0 was published
January 1997 - HTML 3.2 was published
December 1997 - HTML 4.0 was published
December 1999 - HTML 4.01 was published
January 26, 2000 - XHTML 1.0
May 31, 2001 - XHTML 1.1
XHTML 2.0 was a working draft, but work on it was abandoned in 2009 in favor of work on HTML5
May 2011 - HTML 5 (Final in 2014)