Book excerpt: Haptics is a topic which, in recent years, has gained significant attention from several research fields, including computer graphics, robotics, human-computer interfaces, and virtual environments. Through the use of computer controlled forces, a user is given tactile and kinesthetic cues about the underlying application. These cues enhance the overall quality of the application, or possibly add a new dimension, by allowing the user to experience first-hand some previously unavailable phenomena (e.g., hardness, softness, mass, inertia).