  High-performance scientific applications require more and more compute power.
The concurrent use of multiple distributed compute resources is vital for
making scientific progress. The resulting distributed system, a so-called
Jungle Computing System, is both highly heterogeneous and hierarchical,
potentially consisting of grids, clouds, stand-alone machines, clusters,
desktop grids, mobile devices, and supercomputers, possibly with accelerators
such as GPUs.
  One striking example of applications that can benefit greatly of Jungle
Computing Systems are Multi-Model / Multi-Kernel simulations. In these
simulations, multiple models, possibly implemented using different techniques
and programming models, are coupled into a single simulation of a physical
system. Examples include the domain of computational astrophysics and climate
modeling.
  In this paper we investigate the use of Jungle Computing Systems for such
Multi-Model / Multi-Kernel simulations. We make use of the software developed
in the Ibis project, which addresses many of the problems faced when running
applications on Jungle Computing Systems. We create a prototype Jungle-aware
version of AMUSE, an astrophysical simulation framework. We show preliminary
experiments with the resulting system, using clusters, grids, stand-alone
machines, and GPUs.
