DocBook
From Wiki
The main selling point for DocBook is its portability. A document written in DocBook markup can be converted into XHTML, PostScript, PDF, RTF, DVI, and plain ASCII text easily and quickly without any expensive tools. In fact, DocBook and all of the tools used to work with DocBook are freely available under open source licenses. DocBook documents are plain text, and can be edited with any text editor or word processor that can save documents as plain ASCII text. Note that if you use a word processor, take extra care to save DocBook documents as plain text; otherwise they will not parse correctly. If you'll want to use your documentation in more than one format, like print and online, you'll find DocBook is a great solution.
Another advantage of DocBook is that it frees the author from worrying about the formatting and layout of a document: DocBook is only concerned with the structure of a document.
References
- DocBook 5: The Definitive Guide by Norman Walsh
- DocBook XSL: The Complete Guide by Bob Stayton
- DocBook Project at Sourceforge
- The Linux Documentation Project (www.tldp.org) contains many documents written in DocBook.
- OASIS DocBook Pages (http://www.oasis-open.org/specs/index.php#dbv4.1 )
- XML Mind Editor, standard edition, http://www.xmlmind.com/

