Tic Tac Toe is programmed in Python 3.5.3 using the standard library.

tic_tac_toe.py is the main program that runs the game with a graphical user interface made with Tk.

tic_tac_toe_command_line.py is a command line version of the program.

Both uses the program engine.py that computes the moves.

The directory testing_and_research is not needed for playing the game, but includes programs that have been used for developing the game.