OPMOR is a hierarchical. interactive, window-based, graphical oriented software environment for the specification, simulation, performance evaluation. and optimization of motion control algorithms for inobile robots. The software environment allows the definition of the robot operating environment, the robot sensors, the robot geometry, and the specification, development, and testing of sensorbased mobile robot control software. A feature of OPMOR is the simulation of real sensors, real operating environments, and actual robots. Robot control software developed under OPMOR runs with minor modifications on two mobile robots existent at the UPM. The software environment has its own graphical user interface (CUI) implemented on X-Windows. Structured, unstructured, static, and dynamic environments can be modeled with OPMOR. Although OPMOR can be used to simulate any motion control paradigm, we have successfully used it to study reactive systems using behavioral control strategies. Many configurations for the operating environment has been tried using a wide variety of algorithms and implementations and some results are presented. Portions of this research has been performed under the EEC ESPRIT 2483 Panorama Project.