The problem of star formation is presently actively studied both observationally and theoretically. The Principal Investigator proposes to model numerically the collapse of a protostellar cloud into a young stellar object, using 3-dimensional hydrodynamics. The goal is to improve on the existing sets of calculations of this kind by making the physics more realistic: including magnetic effects in the starting models, mass loss through stellar winds, and rotational instabilities. He also proposes to improve the spatial resolution and numerical accuracy of the calculations.