PLUTO is a freely-distributed software for the numerical solution of mixed hyperbolic/parabolic systems of partial differential equations (conservation laws) targeting high Mach number flows in astrophysical fluid dynamics. The code is designed with a modular and flexible structure where by different numerical algorithms can be separately combined to solve systems of conservation laws using the finite volume or finite difference approach based on Godunov-type schemes.
PLUTO is a highly portable software and can run from a single workstation up to several thousand processors using the Message Passing Interface (MPI) to achieve highly scalable parallel performance.

More information at the PLUTO home page