Arpack++ with patches (C++ interface to ARPACK)

Linear solvers in JAX and Equinox. https://docs.kidger.site/lineax

Easy-to-use linear and non-linear solver

MUMPS via CMake

BLAS++ is a C++ wrapper around CPU and GPU BLAS (basic linear algebra subroutines), developed as part of the SLATE project.

Fast and full-featured Matrix Market I/O library for C++, Python, and R

C++ Template Linear Algebra PACKage

CUDA Templates for Linear Algebra Subroutines

This is a Julia package of nonlinear solvers. These codes are used in my book, Solving Nonlinear Equations with Iterative Methods: Solvers and Examples in Julia.

The umfpack scikit provides wrapper of UMFPACK sparse direct solver to SciPy.

Distributed multigrid linear solver library on GPU