AMUSE uses python to couple many different existing (and new) astrophysical simulation codes with a consistent interface. This is combined with a powerful datamodel and many tools for units, i/o and setting up initial conditions. AMUSE includes dozens of these existing codes and it is used all over the world for scientific research and teaching.
AMUSE (Astrophisical MUltipurpose Software Environment) started as small project to couple a number of gravitation dynamics and stellar evolution codes. However, with a dedicated team of developers and a large international user base, it has grown over the past 10 years to become a great research tool. The consistent python interface makes it possible set up fast high quality simulations in a matter of hours (or as a classroom experiment). As creator Simon Portegies Zwart says: "Our aim is to provide a software framework for astrophysical simulations, in which existing codes from different domains, such as stellar dynamics, stellar evolution, hydrodynamics and radiative transfer can be easily coupled." For more information, see amusecode.org.