Computer wins. Better luck next time.
O | X | X ---+---+--- X | X | ---+---+--- O | O | O
Moves: X5 O1 X2 O8 X3 O7 X4 O9
New game | Computer goes first | Undo
Play the recursive version ↻
No JavaScript. Every square is a link. Works in curl, lynx, or a browser.