Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Racer (in full: Racer Free Car Simulation) is a free gaming simulator that runs on Microsoft Windows, Linux, and Mac OS X. Although Racer started out as a driving simulator, it also has features that are usually seen in racing games, such as racing against AI cars, or against human opponents in multiplayer mode. Among its strong points are a very realistic physics engine (also used in a commercial racing simulator), and good graphics. The great graphics come from an advanced shader system, allowing live reflections and other effects. Its weak points, when compared with commercial racing games, is the absence of wear/damage physics or a career mode.