This document describes the source code for a 3D tic-tac-toe game written in Ring. It loads necessary libraries, initializes the game, and defines several classes to handle different aspects of the game like the game logic, background, cubes, interface, and checking for a winner. Key aspects include representing the game board as a 3D array, tracking the active player, mapping mouse clicks to board positions, and checking the board array after each turn to detect a win condition.