We will rely on docker and use a virtual Ubuntu Linux installation that has OpenFoam and HydrothermalFoam installed. For this purpose we have modified the official OpenFoam docker image, so that it also contains all components of HydrothermalFoam. The way docker works is that a so-called docker image is downloaded and from this image a so-called docker container is built, which is the actual virtual environment, see Download OpenFOAM