Multibody dynamics is the branch of physics concerned with the motion of interconnected rigid or flexible bodies and the forces that are responsible for this motion. One of the fundamental objectives in this field is the automatic generation of the equations governing the motion of a multibody system, given a description of its components and the interconnections between them. This book focuses on the development of a framework for the automatic generation of systems of kinematic and dynamic equations that are suitable for real-time applications. In particular, the efficient simulation of constrained multibody systems is addressed. The proposed approach is applied to the simulation of several mechanical systems, including six-bar mechanisms, parallel robots, and two vehicle suspensions, one of which is implemented in a hardware- and operator-in-the-loop driving simulator. The approach developed herein is particularly suitable for situations requiring very efficient simulations of multibody systems whose parameters remain constant, such as the plant models in model-predictive control strategies and the vehicle models in driving simulators.