An equipment mounting system and assembly for rapid mounting and supporting of a fixture mount and a fixture or other equipment, such as motion picture production fixtures and other similar equipment, to a mount support base without fasteners. The equipment mounting assembly can comprise one or more fixture mounts having a base plate and a fixture coupling extending from the base plate, the one or more fixture mounts being operable with an equipment mounting system comprising a mount support base having an upper surface, and a retention system operable to selectively and releasably and interchangeably capture and secure one or more fixture mounts to the mount support base. The retention system can comprise a position keep system capable of applying a biasing force to a captured fixture mount. The equipment mounting assembly and the retention system can be configured to accommodate fixture mounts of different sizes or types.