Mercurial's documentation is kept in reStructuredText format, which is a simple plain text format that's easy to read and edit: http://docutils.sourceforge.net/rst.html It's also convertible to a variety of other formats including standard UNIX man page format and HTML. You'll need to install Docutils: http://docutils.sourceforge.net/ Use the Makefile in this directory to generate the man and HTML pages.