The current version of PETSc is 3.15; released March 30, 2021.

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, and GPUs through CUDA or OpenCL, as well as hybrid MPI-GPU parallelism. PETSc (sometimes called PETSc/Tao) also contains the Tao optimization software library.

News, book on PETSc, by Ed Bueler: PETSc for Partial Differential Equations: Numerical Solutions in C and Python (paper) or at Google Play (E-book)

News, paper on GPU PETSc: Toward Performance-Portable PETSc for GPU-based Exascale Systems

News, source code for petsc4py, developed by Lisandro Dalcin, is now distributed with the PETSc source and supported by the PETSc team and mailing lists

PETSc is developed as open-source, requests and contributions are welcome.