The design of-a robotic manipulator system involves complex computations for solving nonlinear, coupled dynamical equations. Our goal to resolve the design difficulties was to have a general program package combining the following capabilities: (i) a high- level input environment with computer aided-design (CAD) features for constructing, and modifying models of a robot manipulator and its environment; (ii) automatic formulation of kinematic and dynamical equations; (iii) dynamical joint torque (force) calculatione; (iv) an interactive environment for simulation, and task planning; a high-level language for robot programming, and an interactive editor for program debugging. A program with the above capabilites would be attractive because it would allow the user to write and debug robot programs and to plan, simulate, and modify robot manipulator designs in a single programming environment. The Object-oriented Manipulator Design Exerciser (OOMANEX), a soft-ware package for modeling, design and optimization of a robotic manipulator system has been developed to realize the above goals.