rFactor is an upcoming multi-class racing sim from Image Space Incorporated, the creators of SportsCar GT, the F1 and NASCAR games from EA, and the GTR game engine. It will be generic, meaning no official series licences (like NASCAR, FIA GT, F1, etc.) will be used. The game engine they are using is a new one, and not the one used in GTR. The game is supposed to be highly moddable, so expect to see mods such as CART, and NASCAR once the game is out.