Whiskycode is a webpage describing some of our codes to evolve the equations of general relativistic hydrodynamics (GRHD) and magnetohydrodynamics (GRMHD) in 3-dimensional Cartesian coordinates on a curved dynamical background. We develop the Whisky codes to compute matter dynamics, magneti fields and gravitational radiation waveforms for astrophysical systems where general relativity is important. We focus especially, but not only, on mergers of binary systems containing neutron stars. Such systems are expected to be reasonably common in the universe and are known to produce substantial amounts of gravitational radiation, as proved by the measurement of GW170817.

The first Whisky code was originally developed by and for members of the EU Network on Sources of Gravitational Radiation and is based on the Cactus Computational Toolkit. Whisky can also be used with adaptive mesh refinement (AMR) if compiled together with Carpet.

At its birth, Whisky had grown from earlier codes such as GR3D and GRAstro_Hydro (developed by the relativity group at Washington University at the beginning of the century as part of the NASA Neutron Star Grand Challenge Project), but has been completely rewritten.

A public GRHD version of Whisky is available on the Download page. This version was the starting point for the GRHydro code of the Einstein Toolkit, a publicly-available software collection for numerical relativity. Subsequently, GRHydro has been completely rewritten and is now developed and updated independently.