PETSc is an algebraic solver and ODE integrator library with additional tools to help users manage parallel PDE simulations. PETSc contains interfaces to many FASTMath products including hypre, SuperLU, ML, and Zoltan as well as most open source numerical libraries including ParMETIS and MUMPS. PETSc is also used by many simulation frameworks including Deal.II, MOOSE, libMesh, Fluidity, FEniCS, pyClaw, and PetIGA. PETSc also has active development projects with the Chombo and MOAB PDE solver packages.
Usage and applications: PETSc was downloaded over 40,000 times in 2013. It has been cited in over 2,000 scientific publications and has been used by several Gordon Bell applications and Department of Energy application codes