Hybrid Optimization Parallel Search PACKage HOPSPACK solves derivative-free optimization problems in a C++ software framework. The framework enables parallel operation using MPI (for distributed machine architectures) and multithreading (for single machines with multiple processors or cores). Optimization problems can be very general: functions can be noisy, nonsmooth and nonconvex, linear and nonlinear constraints are supported, and variables may be continuous or integer-valued. HOPSPACK is released with two user communities in mind: those who need an optimization problem solved, and those who wish to experiment with writing their own derivative-free solvers.