Instructions for downloading and starting the game with Mountain Lion (this applies to Lion also, but you don't have to hold down the Control key when you double click to start the game).
After you click (farther down on web page you just came from) to download the game, it will be downloaded to your "Downloads" folder (in the Dock on the right side near the trash can).Open the downloads folder to find the downloaded file - DGammXXX.dmg (the XXX is the version number).
Click on the DGammXXX.dmg file icon to open it. A window will open with the game folder and instructions for installing it.
At this point you can install it or just double click on the "David's Backgammom" folder then double-click on the game (David's Backgammon) to start the game.
Important: When you double-click on the game, hold down the Control key, then select "open" from the pop-up menu. Then select the "open" button to start the game. The next time you want to start the game you won't need to hold down the control key.
Sorry for the inconvience of this but this is what Apple requires.