Julia's documentation is written in Markdown. A reference of all supported syntax can be found in the manual. All documentation can be found in the Markdown files in doc/src/ and the docstrings in Julia source files in base/ and stdlib/.
This documentation is built using the Documenter.jl package.
All dependencies are automatically installed into a sandboxed package directory in doc/deps/ to avoid interfering with user-installed packages.
To build Julia's documentation run
$ make docsfrom the root directory. This will build the HTML documentation and output it to the doc/_build/ folder.
To run the doctests found in the manual run
$ make -C doc doctest=truefrom the root directory.