A physics engine widely used in robotics research to model and simulate articulated mechanical systems with contacts. It provides accurate representations of rigid body dynamics, joint constraints, friction, and collisions, which are essential for studying robotic manipulation, locomotion, and control. In robotics, MuJoCo is commonly used to evaluate both traditional control algorithms and learning-based approaches under controlled and repeatable conditions. Its ability to simulate complex physical interactions at high speed makes it suitable for testing control strategies before deploying them on real hardware. MuJoCo plays an important role in bridging theoretical robotics models with practical experimentation, allowing researchers to analyze system behavior, stability, and performance in simulated environments.