Nice that's cool. I kind of worked backwards for this because I wanted to try MCTS so I picked connect4 because I thought it'd be a good game for it. I'm hoping to play some more games soon and try some other approaches. Kalah is a good one.
Hey, author here.
I've wondered that myself. It's not quite as "built in" to other languages as it is in JavaScript but if there was a good implementation it could probably work well. Something to look into.
Thanks! PHP is a highly requested language for us and we've been rolling them out based on demand. You can vote for it if you want here https://github.com/osohq/oso/issues/791