[spawkfish]

1) Its not open source. I'll consider releasing the code at some point when the project is more mature.

2) The Go engine has a lot of pieces I don't have yet. What I have is similar to the policy network from the Go engine, but right now I don't have anything like the value network or the rollout parts. Also,

3) The current engine has no search at all. Behind the scenes the network ranks all of the moves, and then I walk down the list and choose the highest ranked legal move. The top ranked move is almost always valid, but occasionally one or two need to be rejected. It's very very rare to need to search outside of the top 5.

Search is definitely on the agenda, but I am pleasantly surprised at how well it plays without it.

4) Not yet :)

5) I'm using kingbase for training data (http://www.kingbase-chess.net/)