PETSc

PETSc, pronounced PET-see (the S is silent), is a suite of data structures and routines for the scalable (parallel) solution of scientific applications modeled by partial differential equations. It supports MPI, shared memory pthreads, and GPUs through CUDA or OpenCL, as well as hybrid MPI-shared memory pthreads or MPI-GPU parallelism.

http://www.mcs.anl.gov/petsc/

That's nice dear, now turn off the Internet and come to bed.

Bumping the only actually useful thread in here.

>>3
How about you actually make useful posts in here?

>>4
That doesn't sound very fun.