TORCS, The Open Racing Car Simulator is a highly portable multi platform car
racing simulation. It is used as ordinary car racing game, as AI racing game
and as research platform. It runs on Linux (x86, AMD64 and PPC), FreeBSD,
MacOSX and Windows.
The new version features reworked and new tracks and cars, bugfixes and
new features. Have a look into the release notes for details.