The Hardware in the Loop development project is intended to return considerable (~5%) successful observing time annually to the astronomy community through reductions in allocation of production hardware test resources. This is accomplished by providing a simulation platform that attempts to incorporate, in a flexible way, as much of the actual hardware as feasible. In the most realistic case, four actual antennas would be correlated with 12 simulated antennas to provide some real, on-sky data, running on a completely different software/firmware setup, without any impact whatsoever on PI science. It is also a potential source of time saving in the commissioning of major development projects