Webots is a free and open source 3D Robot Simulator for Linux, MacOS and Windows. Using this you can model, program and simulate industrial arms, bipeds, , aerospace vehicle, multi-legs robots, modular robots, automobiles, flying drones and autonomous underwater vehicles and all type of robots in your system. It comes with robots, sensors, actuators, objects and materials asset library for easy design. You can import your CAD models from Blender and URDF. It is based on Open Dynamics Engine physics engine and OpenGL rendering engine. It is released under Apache 2.0 license.