Apps similar to Documatt Snippets include Sphinx, which is free and open source. Other options are Read The Docs. Between them they cover Mac, Windows, Linux, the web and self-hosting.
Sphinx is a tool that makes it easy to create intelligent and beautiful documentation, written by Georg Brandl and licensed under the BSD license.
Germany
EU
Read the Docs hosts documentation for the open source community. It supports Sphinx docs written with reStructuredText, and can pull from your Subversion, Bazaar, Git, and Mercurial repositories. The code is open source, and available on github.
