Docbook - docment type for IT documentation, created by HaL Computer Systems and O'Reilly & Associates 1991.
From 1994 onwards controlled by an official technical committee with members from O'Reilly, Sun, Novell, Hewlett-Packard, Unisys, Digital and others. Public, open development process.
Starting with version 4, DocBook is maintained as both SGML and XML.
See DocBook.Org, DocBook Technical Committee, docbook.sourceforge.org