[Computer-go] public valid move generator algorithms?

[holger krekel]

Hello,

could anyone point me to a current good public source algorithm
for generating valid moves from a given Go board position?

All else failing, i am going to analyze Gnugo first (board.c mostly)
but wanted to ask for hints here first.  I am mostly interested in
readability of the algorithm, not speed, at this point.  So high-level
language implementations are fine.

many thanks,
holger