Benchmarking has been recognized as an efficient tool for model validation as well as scientific collaboration. Several workshop series have been established to foster the benchmarking idea: setting up test cases with increasing complexity for method development and code comparison. In addition to representing model complexity, one of the key efforts is to develop codes that are suitable for modern HPC platforms such as PetaFlop supercomputers. It has been realized that those challenges are beyond single team capabilities. Some of these ongoing initiatives are, for example, Sim-SEQ (Mukhopadhyay et al. 2012, 2015), CO2BENCH (for CO2 storage) (Kolditz et al. 2012a), DECOVALEX (1.1), SeS-Bench (1.2) (Steefel et al. 2014) and MoMaS (1.3) (Ackerer 2010).