HYPRE - http://www.llnl.gov/casc/hypre/
HYPRE is a library of high performance preconditioners and solvers featuring multigrid methods for the solution of large, sparse linear systems of equations on massively parallel computers.
Documentation can be found at https://hypre.readthedocs.io/en/latest/.
To install HYPRE, please see either the documentation or the file INSTALL.md.
An overview of the HYPRE release history can be found in the file CHANGELOG.
We appreciate feedback from users of this package. Please submit comments, suggestions, and issue reports to hypre-support@llnl.gov.
Legal stuff (copyright, disclaimer, licensing restrictions, etc.) can be found in the file COPYRIGHT.
HYPRE is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License (as published by the Free Software Foundation) version 2.1 dated February 1999.