Replying to self. :)

As a starting point, a Google Code project has been created. You can
find it at:
http://code.google.com/p/robowarx/

I've checked in the source there, and did a tad of additional work on it:

* Got the GTK+ GUI in a somewhat working state again. It now uses the
GtkUIManager, though MonoDevelop doesn't seem to integrate with that
yet. (Looks like it's planned for MD 2.0.)

* Added the very basic text-only robot format. (The example code in my
last mail was rather trashy, tbh.) Simply create a text file with the
.rtxt extension and open it.

Randall, I'll need your Google account name to add you as project owner.

-- Stéphan