MUMPS: a parallel sparse direct solver
MUMPS (MUltifrontal Massively Parallel Solver) is a package for solving systems of linear equations of the form Ax = b, where A is a square sparse matrix that can be either unsymmetric, symmetric positive definite, or general symmetric, on distributed memory computers. MUMPS implements a direct method based on a multifrontal approach which performs a Gaussian factorization.