midish: portmidi port feasible

Hi,

I'm positively surprised to find a program like midish! One questions
pops up though: is it portable to other OSes? I'd like to be able to use
it on Windows and OS X too.
Glad to find an mdep.c with os-specific functions, I still wonder if it
would be possible to use a cross-platform midi library like portmidi or
midiio (*) without having to mess up the source code too much.
I hope you can give me some insight on this.

Kind regards,
- Willem van Engen

(*) They can be found at http://portmedia.sourceforge.net/ and
http://midiio.sapp.org/ respectively.