For posting:
- invitations to games (you can also use the New Game menu)
- information about upcoming tournaments
- discussion of games (please limit this to completed games or discussion on how a game has arrived at a certain position ... speculation on who has an advantage or the benefits of potential moves is not permitted)
- links to interesting related sites (non-promotional)
wetware: Good old Compromise Chess is also a nice game, it is indeed the variant closest to Ambiguous Chess. It looks like it is usually played with the rule that if you have only one move to get out of check, your opponent has to accept it. However, I prefer the "wild" rule that in such a case you lose the game (because your opponent will capture your king).