Tic-Tac-Toe

David Molnar's Tic-Tac-Toe Variants
Describes variants on the game.
http://www.stolaf.edu/people/molnar/games/ttt/animals.html

Guy Fawkes's Analysis of Boolean Tic-Tac-Toe
Analysis of variant that allows anti-play.
http://www.chiark.greenend.org.uk/~dricher/Nomic/Acka/subgames/bttt-analysis.html

The History of Noughts and Crosses
Article on the game's history.
http://www.adit.co.uk/html/noughts_and_crosses.html

Math Lair - Tic-Tac-Toe
Game variations, looking from the mathematical side
http://www.stormloader.com/ajy/tictactoe.html

Pencil & Paper Games Plaza: Tic Tac Toe
Instructions for game play.
http://www.xs4all.nl/~spaanszt/PencilPaperGames/TicTacToe.html

Tic Tac Toe In Brief
Rules, variations, strategy, theory and practice. Includes an online version of the game.
http://www.tic-tac-toe-online.com/

Tic Tac Toe Strategy Solutions
Details a step-by-step process that allows the first player to win or draw, but never lose.
http://www.chessandpoker.com/tic_tac_toe_strategy.html

Tic Tac Toe Top Secret
Description of a strategy against a member of the group that allows one to win or to draw.
http://www.askapastor.org/tictac.html

Tic-Tac-Toe Strategy
Features explanations and the opportunity to put the advice into practice.
http://ostermiller.org/tictactoeexpert.html