dependency on a2x for making man pages

[Tomas Nordin]

Hello list

I have I think a very simple question. For making man pages there is a
dependency on a2x, stated in the README.md as

    $ make man   # Requires a2x

Is this the python package at

    https://pypi.python.org/pypi/a2x

If not, what is it?

Best regards
--
Tomas