Hi, I am interested in simulating the vacuum field equations, but solving a full boundary value problem rather than the initial value problem. i.e. I might have boundary conditions in all spatial and temporal extents/extremes, rather than just an initial 3D surface. Does anyone know any free software that could perform such a simulation? I have started looking at the Einstein Toolkit docs and it doesn't really look like it does this, and I don't have much info on GRCombo. many thanks, Tom.