A method for developing maneuvering control strategies using optimal control theory is presented. A computer code, OPXENON, based on Pontryagin's Principle, has been written, tested, and applied to maneuvering control problems. It uses modified one-group diffusion theory with Doppler and moderator feedback, and is able to handle up to 20 mesh points in one dimension and 100 time steps. The neutronics have been verified by comparison with standard maneuvering codes, and the Euler-Lagrange solution has been verified by comparison to known optimization results. Convergence to the optimal or near-optimal control is obtained within a few iterations. The code is particularly useful when there are several conflicting performance criteria. It has been applied to the problem of minimizing the boron interchange during a pressurized water reactor maneuver while maintaining acceptable shapes.