AnimatLab is a neuromechanical and neurorobotic simulator that allows authors to build the body of a robot or biolgical organism in a physically accurate 3-D virtual world, and then layout a biologically realistic nervous system to control the animats behavior. It is made of a GUI editor and a simulation system. The simulator was originally based on the Vortex physics engine from cm-labs. Recently a new physics plug-in for the Bullet physics engine was added. This allowed all the source code for the simulator to be 100% open source and available in this repository. The GUI is almost entirely open-source as well. There are some 3rd party controls that it uses that are no open-source, and there is a licensing component for the GUI editor that is closed source. The simulator is totally free, but the GUI editor comes in a free, feature-limited standard version and a fully functional Pro version that is available for purchase at www.AnimatLab.com. For more information on how to use AnimatLab please see the website. It has full documentation and over a hundred video tutorials describing how to use the system.