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.
Greenhorn displays documentation strings directly from the source code itself, which is handy if you use or write your own modules whose documentation is not keeping pace with development. It uses the PyGTK treeview widget to display a tree diagram of modules in a window. Clicking on individual modules displays . __doc__ strings and sub-modules or functions. Source code can also be browsed, if available, using Python inspect.
The wiki has become the clear choice for use among projects for their help documentation. Wiki Web Help takes the wiki concept and tailors it for use specifically with help documentation. It combines the best of both worlds, with operation similar to a chm viewer and the Web technologies that enable community involvement. It features a dual split pane with tabs for searching, index browsing, and display of contents (in a tree). Users can create and modify topics and pages. Pages can be tagged for index creation. Searching with highlighting is included.
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.