Slipstream is a free multi-body vehicle simulator. Instead of using some sort of specific empirical model of a particular type of vehicle, vehicles are modeled as assemblies of interconnected moving parts. This allows any kind of vehicle to be modeled and moreover the whole model is completely parametric so that everything can be configured from the mass of the chassis to suspension geometry and engine and transmission characteristics. Slipstream can be executed either in real-time or off-line through control scripts and every quantity calculated during the simulation can be logged for plotting or further analysis so it can be used as a game or as a tool to study vehicle dynamics. Currently a modern sports motorcycle model is implemented based on measurements made from such a machine and published in an academic research paper.