This manual discusses the use and interface of the GibbsCAM Machine Sim option. The Machine Simulation option is a 3D representation of a Machine Tool, the parts, and cutting tools. It supplements the standard rendering component of GibbsCAM. Last major update: February 2009, for GibbsCAM 2009, v9.0; last revised January 2015, for GibbsCAM 2015, v11.0