Name: SuperTuxKart

Platform: Windows, Mac, Linux

Download Link: supertuxkart.net
Addons Page: addons.supertuxkart.net

Description:
SuperTuxKart is a 3D racing game similar to Super Mario Kart. SuperTuxKart supports multiplayer racing and AI karts. There are additional tracks, karts and addons that can be downloaded from the SuperTuxKart website.