I'm in the process of rewriting GoFigure, and currently my board library implements a very strict Tromp-Taylor ruleset. Among other things, this means it requires alternating play. It would be possible to extend the library to support non-alternating play, but I'm not yet sure what the right way to do that is.
I would like to suggest that GTP version 3 have some way of allowing engines to support only alternating play.
I could fake the support by inserting a pass move in such cases, but that seems inelegant. Similarly, I'd rather not add a function that plays illegal moves.
Evan Daniel