Whisky is a collection of modules (called thorns) for the Cactus framework, which is part of the the EinsteinTookit. After downloading Cactus, the Whisky thorns can be downloaded here and are to be placed in a subdirectory of Cactus/arrangements/. In order to compile Whisky together with the rest of Cactus, the relevant thorns have to be added to the thornlist before compilation:
# The public version of Whisky
!TARGET = Cactus/arrangements
!TYPE = svn
!URL = https://svn.whiskycode.org/$1/$2/trunk
Here is an example of a complete thornlist.
It is also necessary to add appropriate parameters to the parameter file used when running the executable that has been created. The parameter file would include information like if and how to setup the initial conditions (like the location and type of stars) and how to evolve these data. This example parameter file sets up the evolution of a TOV star using Whisky for a short time, doing some 1D output.