The Pencil Code, a modular MPI code for partial differential equations
  and particles: multipurpose and multiuser-maintained
  The Pencil Code is a highly modular physics-oriented simulation code that can
be adapted to a wide range of applications. It is primarily designed to solve
partial differential equations (PDEs) of compressible hydrodynamics and has
lots of add-ons ranging from astrophysical magnetohydrodynamics (MHD) to
meteorological cloud microphysics and engineering applications in combustion.
Nevertheless, the framework is general and can also be applied to situations
not related to hydrodynamics or even PDEs, for example when just the message
passing interface or input/output strategies of the code are to be used. The
code can also evolve Lagrangian (inertial and noninertial) particles, their
coagulation and condensation, as well as their interaction with the fluid.
