V-REP is the Swiss army knife among robot simulators: you won't find a simulator with more functions, features, or more elaborate APIs.
The robot simulator V-REP, with integrated development environment, is based on a distributed control architecture: each object/model can be individually controlled via an embedded script, a plugin, a ROS node, a remote API client, or a custom solution. This makes V-REP very versatile and ideal for multi-robot applications. Controllers can be written in C/C++, Python, Java, Lua, Matlab, Octave or Urbi.
V-REP is used for fast algorithm development, factory automation simulations, fast prototyping and verification, robotics related education, remote monitoring, safety double-checking, etc.
Commercial licensing option available: http://www.coppeliarobotics.com/licensing.html
LinkedIn --> https://www.linkedin.com/company/v-rep
YouTube --> https://www.youtube.com/user/VirtualRobotPlatform