This splinter meeting will host an open discussion on open source and benchmarking-ready open-data approaches for simulation tools in the field of gravitational mass flows. We want to, but not exclusively, discuss the following: i) benchmarking and model/simulation comparison, ii) open-data common data formats, iii) cascading processes, slow-flows, deformation control and iv) modes of communicating results, including virtual reality interfaces and probabilistic hazard maps.