Write the Docs is a series of conferences and local meetups focused on all things related to software documentation.

Read the Docs hosts documentation, making it fully searchable and easy to find. You can import your docs using any major version control system, including Mercurial, Git, Subversion, and Bazaar.

GitBook is a modern publishing toolchain. Making both writing and collaboration easy.

Do178Builder is a free software tool which helps to structure the software-development effort in such a way that documentation -- and particularly DO-178B documentation -- is a natural product of the project rather than a time-consuming after-thought. Versions of Do178Builder exist for Win32 and for Linux. Source-code is provided, so it may be possible to compile it for other platforms as well.