Date: 2001-10-30 14:52:49

XML History 101

The concept of XML is over 30 years old, beginning in the 1960's. Its origins are in the standardized typesetting codes (GENCODE) used by the publishing industry.
In the 1970's, Dr. C. F. Goldfarb proposed a method of describing text that was not specific to an application or hardware. He created Generalized Markup Language (GML). The basic tenents of GML were:

• 
  markup should emphasize the document structure not format or style
  
• simple input syntax for markup using <> and </> tags
  
  
• markup syntax rules should be strictly controlled so that the code could be easily read by humans or software programs.
  

Originally the number of document types supported by GML was limited so the addition of any new tags and document types was relatively simple. By the 1980's, however, these numbers grew to such an extent that GENCODE and GML proponents formed the ANSI Committee on Computer Languages for the Processing of Text.






In 1986 this committee promulgated Standardized Generalized Markup Language (SGML) which standardized the use of <> and tags, as well as Document Type Definitions (DTD). As with GENCODE and GML, the primary use of SGML was for large-scale publishing.





As interest in the Internet grew, and the functionality of Internet browsers evolved, the need for a standardized hypertext application increased. In the early 1990's the World Wide Web Consortium (W3C) adopted HyperText Markup Language (HTML) as the standard. HTML is a subset of SGML because it borrowed existing tags from SGML and DTD.





As web communities have grown, so has the need to publish new types of documents. Many of these documents are community specific. Unfortunately, HTML cannot be extended to accommodate new document types, and browsers will not support SGML. These needs prompted the W3C to sponsor the development of an "eXtensible Markup Language."

Source : http://www.gegxs.com/gxs/tutorials/tutor/xml5