OpenGeoSys (OGS) is a scientific, open-source project for the development of numerical methods for the simulation of thermo-hydro-mechanical-chemical (THMC) processes in porous and fractured media. OGS is implemented in C++; it is object-oriented with a focus on the numerical solution of coupled multi-field problems (multi-physics). Parallel versions of OGS are available relying on both MPI and OpenMP concepts. Application areas of OGS currently include water resources management, hydrology, geothermal energy, energy storage, CO2 sequestration, and waste deposition. See the following links for further information:
A short history of OGS which is originally based on RockFlow can be found in the OGS Developer Benchmark Book and overview paper below.