Utilities for general- and special-purpose documentation. Includes reStructuredText, the easy to read, easy to use, what-you-see-is-what-you-get plaintext markuplanguage.
pyWeb is a Literate Programming tool that will work with any markuplanguage and any programming langauge. The idea is to allow you to create great documentation with as constraints or limitations.
ZML, the Zeitung MarkupLanguage, is a simple CMS for small newspapers. It was specifically designed to publish a student newspaper in print and on the Web. It uses LaTeX and XHTML. So far, it is documented in German only.
SilverCity is a lexing package, based on Scintilla, that can provide lexical analysis for over 20 programming and markup langauges. Scripting language bindings currently exist for Python.
SchemaDoc is a XML-based markuplanguage for documenting XML schemas. The work products include both the vocabulary and a set of tools for combining it with the schema source (e.g. a DTD) to produce documentation in HTML, XML DocBook, LaTeX, etc.