Sandbox is a mod that lets you use the BF2 engine to build structures, set up racetracks, ramps, and much much more. This is all done from an easy Command Rose interface in-game. There are a variety of objects to choose from when building a creation - and once you're done, you can save it and send it to your friends. Multiplayer support is also included so many players can collaboratively construct buildings, have wars, hit each other with barrels, and anything else they can imagine!
My friends and I have played this mod for what seems like a million hours. So much fun to be had.
You can do almost whatever you want. Buggy races, formation flight practice, dogfight, fort building and so mcuh more! =D
Two thumbs up and a 10/10.