*`os <http://www.lua.org/manual/5.3/manual.html#6.9>`_ (available features vary depending on your OS)
..tip:: For more information about Lua, check out the `Reference Manual <http://www.lua.org/manual/5.3/>`_, the online edition of the book `Programming in Lua <http://www.lua.org/pil/>`_ or the `Lua-users wiki <http://lua-users.org/wiki/>`_.