FoamDSMC: An object oriented parallel DSMC solver for rarefied flow applications. The prevalence of applications involving the simulation of rarefied gas flows continues to increase. As such, new and innovative means for their solution have become necessary. Presented herein, is a new, parallel, steady/unsteady direct simulation Monte Carlo solver, foamDSMC, based on object oriented programming practice. Its development, and validation are presented, along with various single and multiple processor performance characteristics. The validation results, of both the hypersonic corner flow and sphere flow, showed the accuracy of the solver to be comparable to commercial solvers. The foamDSMC solver was additionally applied to a sounding rocket flight, and thus showed its applicability to practical simulations. The single and multiple processor performance results demonstrated good scalability with increased problem sizes and clear avenues for future improvements.