From MIT:

Drake ("dragon" in Middle English) is a toolbox maintained by the Robot Locomotion Group at the MIT Computer Science and Artificial Intelligence Lab (CSAIL). It is a collection of tools for analyzing the dynamics of our robots and building control systems for them in MATLAB and C++, with a heavy emphasis on optimization-based design/analysis. Here is a quick summary of capabilities:

Simulation

• Rigid-body dynamics including contact/collisions (hybrid+LCP) and kinematic loops
• Basic aerodynamics/fluid dynamics
• Sensor models (lidar, depth camera, imu, contact force/torque; cameras coming soon)
• Hand-derived models for many canonical control dynamical systems
• Easily add your own models/components
• Some support for stochastic models
• For all of the above we aim to expose sparsity and provide analytical gradients / symbolic analysis
• Primary limitations: code is optimized for analysis / planning / control design (as opposed to speed, generality)...

​... Most of these models/tools are described in the companion textbook from an MIT course/MOOC. We've also recently started populating the Drake Gallery (contributions welcome!)... (git repo)