Xdemineur is a minesweeper game for the X Window System. The object of this game is to find the location of the mines hidden in the minefield and to mark their location by placing a warning flag. You have exactly as many flags as there are mines. The number of flags that remain to be placed is displayed in the top left corner of the window and a timer is displayed in the top right corner. The game is played using a three buttons mouse, as usual with the X Window System. The left button (button 1) is used to uncover the square on which you click (hoping that a mine is not hidden there). The number displayed in an uncovered square indicates how many mines are located around this square (for example, a 3 means that there are three mines within the 8 surrounding squares). The whole game relies on the right use of these numbers. The right button (button 3) is used to place a flag on a square (this indicates that there is a mine here). If you click again with the right button on a square that has a flag, the flag is changed into a question mark: this is useful if you are trying to guess the possible location of some mine, you can use question marks to think about it. One more click with the right button and the question mark disappears. Clicking with the middle button (button 2) on an uncovered square which has all its flags placed around uncovers the surrounding cells which have no flags (this will save a lot of time).