SDoP (Simple DocBook Processor) reads a DocBook XML file, processes it into typeset pages, and outputs the result as PostScript (which can easily be converted to a PDF). It is "simple" because it supports only a subset of DocBook, and also because it does not make use of a DTD or stylesheets or any other heavyweight apparatus. It is a single program. SDoP is used to format the Exim reference manual.
DokuWiki is a standards-compliant, simple-to-use Wiki mainly aimed at creating documentation of any kind. It is targeted at developer teams, workgroups, and small companies. It has a simple but powerful syntax which makes sure the datafiles remain readable outside the Wiki, and eases the creation of structured texts. All data is stored in plain text files, so no database is needed
Txt2tags converts a text file with minimal markup to HTML, XHTML, SGML, DocBook, LaTeX, Lout, Man page, Creole, Wikipedia, Google Code Wiki, PmWiki, DokuWiki, MoinMoin, MagicPoint, PageMaker, AsciiDoc, or ASCII Art. It is simple and fast and features automatic TOC, macros, filters, include, tools, GUI, CLI, and Web interfaces, translations, and extensive documentation.
Xaraya is a fully dynamic, multi-platform content mangement solution. It utilizes robust permissions, data management, and multilingual systems to dynamically integrate and manage content. Its modular, database-independent architecture introduces tools which separate form, function, content, and design.
xhtml2pdf converts HTML/XHTML/XHML to PDF using the ReportLab Toolkit, the HTML5lib, and pyPdf. It supports HTML 5 and CSS 2.1 (and some of CSS 3). The main benefit of this tool that a user with Web skills like HTML and CSS is able to generate PDF templates very quickly without learning new technologies.