I would like to point out that the Python port has become much more stable and a lot more feature-complete recently

 

And since Sphinx plays nicely with Python, Python natively supports docstrings (actual object attributes), and packages like Redbaron allow for parsing even comments for extended functionality (like documenting features), I'd vote for Sphinx. I know someone else mentioned it, but I haven't heard of Asciidoctor either, so I don't know how widely known it is.

 

Ultimately, however, either choice seems good to me.

 

Aaron