TrackMania - The most popular online PC racing game.
VDrift - VDrift is a cross-platform, open source driving simulation made with drift racing in mind.
Forza Horizon - Forza Horizon is a Marvelous, Action-Adventure, Racing, Single and Multiplayer video game developed by Playground Games and published by Microsoft Studios.
TORCS - TORCS, The Open Racing Car Simulator is a highly portable multi platform car racing simulation.
Nitro Nation Online - Race, mod and tune dozens of real licensed cars. Over 20 million players can’t be wrong! Nitro Nation is the top rated multiplayer racing game experience
Speed Dreams - Speed Dreams is a 3d cross-platform, open source motorsport simulation and racing game.