Syntext Serna is a highly customizable, multi-platform, pure XSL-driven WYSIWYG XML content editor. It looks and works like a conventional word processor, yet it gives you much more flexibility to alter or reuse content while keeping its integrity intact. It lets you collaborate on compound documents that contain embedded data from various sources. Content is viewed as an integrated whole that is intuitively transparent to authors.
AsciiDoc is a text document format for writing short documents, articles, books, and UNIX man pages. AsciiDoc files can be translated to HTML and DocBook markups using the asciidoc(1) command. AsciiDoc is highly configurable: both the AsciiDoc source file syntax and the backend output markups (which can be almost any type of SGML/XML markup) can be customized and extended by the user.
4Suite XML is a Python-based toolkit for XML application development. It features a library of integrated tools for XML processing, implementing open technologies such as DOM, SAX, XPath, XSLT, XInclude, XPointer, XLink, XUpdate, RELAX NG, and XML/SGML Catalogs. The RDF and Repository components of 4Suite are separate packages that must be installed separately, on top of 4Suite XML.
Thot takes as input text in a wiki-like format and outputs results for different formats: HTML, Latex, DocBook, and PDF. Although delivered with only one input language (Dokuwiki format), Thot is very versatile and easy to extend. For example, the initial version allows you to embed a document description from different entities: source language, GraphViz DOT graphs, Latex math, etc.
The DocBook Authoring and Publishing Suite (DAPS) provides a tool set for easy creation and publication of DocBook sources on Linux. It lets you create HTML (including Webhelp), PDF, EPUB, man pages, and other formats with a single command. It automatically takes care of validating and filtering (profiling) your sources and automatically converts images into a format best suited for the output format. You can easily create profiled source tarballs for translation or review. DAPS supports authors by providing linkchecker, validator, spellchecker, and editor macros. It is well suited to manage large documentation projects with multiple authors using the DAPS docmanager.