documentr is a Web-based tool for editing and presenting software documentation. It allows you to easily maintain documentation for multiple products and product branches. Edits can easily be copied between branches, with merge conflicts being handled gracefully. It uses Markdown as its markup language, along with some extensions, and has a role-based permission system.
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.
Doxer provides a wiki-based markup language for writing source code documentation and general purpose documents. It generates HTML output and also provides a Drupal input format module. The parser and HTML generator have a strong focus on robustness to support the full range of user sophistication found on general purpose Web sites. An extensive test suite accompanies the development.
Aephea is a text-based authoring tool for HTML. It enforces well-formedness with a simpler and stricter TeX-like syntax and provides useful extensions and abstractions with facilities for adding new ones. It emphasizes a single unified approach that stays close to HTML itself and promotes and utilizes CSS extensively. Abstractions such as dictionary stacks, arithmetic, and iteration are part of Aephea.
MkDoc is a C and C++ code documentation tool. It parse complex code and still produces clear documentation for developers and library users. Unlike most code generation tools, it does not simply write generated code documentation with pieces of user text inside. Instead it handles plain documentation files with sections and other constructs (like Texinfo or LaTeX) and inserts pieces of generated code documentation on request. Thus it does not enforce any way of structuring your document. It has been designed to parse advanced C++ constructs including class inheritance, template specialization, and template instantiation. XHTML, Texinfo, LaTeX, and DocBook output formats are supported.
The Isotrol DocGen BOUML plugout is a practical tool to update the OpenUP-based documentation of your project dynamically. DocGen extracts texts and diagrams from a BOUML project and inserts them in an OpenOffice.org Writer document. It's preconfigured with a generic project template and three definition files for Analysis, Design, and Architecture OpenUP-based documents. You can also insert predefined tables and link external images to embed them into the document. You can define your own template and file definitions. It's as easy as writing an OpenOffice.org Writer document and designing your own page format, cover, index page, headings styles, variables, etc. Afterwards, you create an XML file pointing to the parts of the BOUML project with the contents.
phpdocr will download, prettify, and output PHP documentation for the function or class that is supplied on the command-line, much like perldoc does for Perl and ri does for Ruby. Unless you explicitly tell it not to, phpdocr will also cache the documentation locally for fast retrieval in the future.
Seetxt is a lightweight text file and man page viewer for X windows. It maintains "document meta-data" for each user, allowing them to automatically keep bookmarks and highlights for read-only system files. It also has a "server mode" so that command line requests can be sent to a single running server rather than starting multiple instances. Other features include hypertext-style apropos (man page) searches, file monitoring, multi-level regular expression searching, a command history, and nice little toggle lights on the interface for the server and file monitor. There's also cross-application drag-n-drop support, and handy little features that allow you to view the output of shell commands and process the text buffer with an external command (sed, awk, grep, perl, etc.) Seetxt is POSIX compliant.