Dotso is an adaptation of the pencil-and-paper game "Dots and Boxes" for MS-DOS PCs. It is distributed as shareware, with license keys available from Soleau Software's website. The shareware game is played against an AI opponent, while the full version allows local multiplayer games as well.
The game takes place on a grid of dots, with players taking turns to draw lines between them. When a single grid cell (or "box") is enclosed on all four sides, it is claimed by the player that drew the fourth line and they get an extra turn. When the grid is completely filled-in, the player with the most boxes wins.
The main difference between Dotso and a traditional game of Dots and Boxes is that Dotso seeds the board with some random lines at the start of each game.