You need GnuGo installed and somewhere on your path.  Python needs to
be able to find pygame.

Click = make a move.  Down = have GnuGo make a move.  Up = go back to
explore other possibilities.

Play around. 

On my Mac, clicking on the program icon causes the game to crash.
Seems to be a pygame bug (not related to the frivolous icon updating),
so switch programs using command-tab or something instead.