The official SuiteSparse library: a suite of sparse matrix algorithms authored or co-authored by Tim Davis, Texas A&M University.

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

Test cases demonstrating different sparse matrix libraries

GETS: a Genomic Tree based Sparse solver. This package accompanies an article to be published in the forthcoming Birkhäuser-ANHA book "Explorations in the Mathematics of Data Science" --- "A genomic tree based sparse solver" by Timothy A. Davis and Srinivas Subramanian.