The Portable, Extensible Toolkit for Scientific Computation (PETSc, pronounced PET-see; the S is silent), is a suite of data structures and routines developed by Argonne National Laboratory for the scalable (parallel) solution of scientific applications modeled by partial differential equations.

PETSc is the world’s most widely used parallel numerical software library for partial differential equations and sparse matrix computations.

[1][2][3] The PETSc Core Development Group won the SIAM/ACM Prize in Computational Science and Engineering for 2015.

PETSc includes a large suite of parallel linear and nonlinear equation solvers that are easily used in application codes written in C, C++, Fortran and now Python.

In addition, PETSc includes support for parallel distributed arrays useful for finite difference methods.