Mujoco

MuJoCo (Multi-Joint dynamics with Contact) is a high-performance, open-source physics engine designed for accurate and efficient simulation of articulated bodies and complex contact dynamics. Its primary purpose is to support research and development in robotics, biomechanics, computer graphics, animation, and reinforcement learning by providing a precise model of physical interactions. MuJoCo emphasizes numerical stability and performance, making it suitable for both real-time control and large-scale offline simulation workloads.

MuJoCo offers a detailed modeling language (MJCF) for specifying multi-body systems, joints, actuators, and sensors, as well as sophisticated contact modeling with friction, soft constraints, and customizable geometry. It uses advanced numerical integration and optimization-based contact solvers to handle stiff systems and highly constrained dynamics reliably. The engine supports inverse dynamics, forward dynamics, and kinematics, along with automatic differentiation for gradient-based optimization and learning. Integrated visualization tools and APIs for C, Python, and other languages enable seamless integration into research pipelines, simulation frameworks, and custom tooling.