MuJoCo

MuJoCo is a physics simulation engine designed for robotics research, computer graphics, and machine learning applications. It provides fast and accurate simulation of contact dynamics, making it particularly useful for researchers and engineers developing robot control algorithms, testing virtual prototypes, or training reinforcement learning agents in simulated environments. The engine handles complex multi-body dynamics with joints, actuators, and sensors, allowing users to model articulated systems like robotic arms, legged robots, and other mechanical assemblies.

MuJoCo is available as a free and open-source tool, having transitioned to this model after being acquired by DeepMind. Researchers can download and use the software without licensing fees, which has made it widely adopted in academic settings and open research projects. A typical use case involves training a simulated quadruped robot to walk: researchers define the robot's physical structure, implement control policies, and run thousands of simulated episodes to optimize locomotion strategies before deploying code to physical hardware. This approach significantly reduces development time and hardware wear compared to training directly on real robots.