This is a very simple tic-tac-toe program. I wrote it 2 years ago when I just learnt Java. The GUI comes from Netbean's template. BetaGo 2.1 is the revisted version for BetaGo 1.0. The source code(BetaGo) is for the 1.0 version.
Version 2.1 is smarter. It is impossible to beat. So is more fun to play with BetaGo 1.0. If you play all moves perfectly, you will have 50% to win and 50% to tie.