David Molnar's Tic-Tac-Toe Variants: Describes variants on the game.
Guy Fawkes's Analysis of Boolean Tic-Tac-Toe: Analysis of variant that allows anti-play.
Math Lair - Tic-Tac-Toe: Game variations, looking from the mathematical side
Pencil & Paper Games Plaza: Tic Tac Toe: Instructions for game play.
The History of Noughts and Crosses: Article on the game's history.
Tic Tac Toe In Brief: Rules, variations, strategy, theory and practice. Includes an online version of the game.
Tic Tac Toe Strategy Solutions: Details a step-by-step process that allows the first player to win or draw, but never lose.
Tic Tac Toe Top Secret: Description of a strategy against a member of the group that allows one to win or to draw.
Tic-Tac-Toe Strategy: Tic-Tac-Toe strategy with explanations and opportunity to put the advises into practice.