DocBook is a very popular set of tags for describing books, articles, and other prose documents, particularly technical documentation. DocBook is defined using the native DTD syntax of SGML and XML. Like HTML, DocBook is an example of a markup language defined in SGML/XML.
DocBook is almost 10 years old. It began in 1991 as a joint project of HaL Computer Systems and O'Reilly. Its popularity grew, and eventually it spawned its own maintenance organization, the Davenport Group. In mid-1998, it became a Technical Committee (TC) of the Organization for the Advancement of Structured Information Standards (OASIS).
The DocBook DTD was originally designed and implemented by HaL Computer Systems and O'Reilly & Associates around 1991. It was developed primarily to facilitate the exchange of UNIX documentation originally marked up in troff. Its design appears to have been based partly on input from SGML interchange projects conducted by the Unix International and Open Software Foundation consortia.
When DocBook V1.1 was published, discussion about its revision and maintenance began in earnest in the Davenport Group, a forum created by O'Reilly for computer documentation producers. Version 1.2 was influenced strongly by Novell and Digital.
In 1994, the Davenport Group became an officially chartered entity responsible for DocBook's maintenance. DocBook V1.2.2 was published simultaneously. The founding sponsors of this incarnation of Davenport include the following people:
Jon Bosak, Novell
Dale Dougherty, O'Reilly & Associates
Ralph Ferris, Fujitsu OSSI
Dave Hollander, Hewlett-Packard
Eve Maler, Digital Equipment Corporation
Murray Maloney, SCO
Conleth O'Connell, HaL Computer Systems
Nancy Paisner, Hitachi Computer Products
Mike Rogers, SunSoft
Jean Tappan, Unisys
Under the auspices of the Davenport Group, the DocBook DTD began to widen its scope. It was now being used by a much wider audience, and for new purposes, such as direct authoring with SGML-aware tools, and publishing directly to paper. As the largest users of DocBook, Novell and Sun had a heavy influence on its design.
Minor versions (“point releases” such as
V2.2) could add to the markup model, but could not
change it in a backward-incompatible way. For example, a new kind of
list element could be added, but it would not be acceptable for the
existing itemized-list model to start requiring two list items inside
it instead of only one. Thus, any document conforming to version
n.0 would also conform to
Major versions (such as V3.0) could both add to the markup model and make backward-incompatible changes. However, the changes would have to be announced in the last major release.
Major-version introductions must be separated by at least a year.
V3.0 was released in January 1997. After that time, although DocBook's audience continued to grow, many of the Davenport Group stalwarts became involved in the XML effort, and development slowed dramatically. The idea of creating an official XML-compliant version of DocBook was discussed, but not implemented. (For more detailed information about DocBook V3.0 and plans for subsequent versions, see Appendix B, DocBook Versions.)
The sponsors wanted to close out Davenport in an orderly way to ensure that DocBook users would be supported. It was suggested that OASIS become DocBook's new home. An OASIS DocBook Technical Committee was formed in July, 1998, with Eduardo Gutentag of Sun Microsystems as chair.
The DocBook Technical Commitee is continuing the work started by the Davenport Group. The transition from Davenport to OASIS has been very smooth, in part because the core design team consists of essentially the same individuals (we all just changed hats).
DocBook V3.1, published in February 1999, was the first OASIS release. It integrated a number of changes that had been “in the wings” for some time.
In February of 2001, OASIS made DocBook SGML V4.1 and DocBook XML V4.1.2 official OASIS Specifications.
Version 4.2 of the DocBook DTD, for both SGML and XML, was released in July 2002.
The committee continues new DocBook development to ensure that the DTD continues to meet the needs of its users. Forthcoming and experimental work includes: