MOOSE (Multiphysics Object Oriented Simulation Environment) is an object-oriented C++ finite element framework for the development of tightly coupled Multiphysics solvers from Idaho National Laboratory. MOOSE makes use of the PETSc non-linear solver package and libmesh to provide the finite element discretization. Current applications of the MOOSE platform include:

Bison: Fuel performance analysis
Rattlesnake: Multigroup radiation transport
Marmot: Microscopic materials aging and degradation
Mammoth: Rector multiphysics analysis
Grizzly: Component aging
Mastodon: Nonlinear seismic analysis

Additional information can be found on the MOOSE homepage at moose.inl.gov.