The BLAS (Basic Linear Algebra Subprograms) are high quality "building
block" routines for performing basic vector and matrix
operations. Level 1 BLAS do vector-vector operations, Level 2 BLAS do
matrix-vector operations, and Level 3 BLAS do matrix-matrix
operations. Because the BLAS are efficient, portable, and widely
available, they're commonly used in the development of high quality
linear algebra software, LINPACK and LAPACK for example.

LAPACK is a highly portable Fortran 77 library which provides routines
for solving systems of simultaneous linear equations, least-squares
solutions of linear systems of equations, eigenvalue problems, and
singular value problems. The associated matrix factorizations (LU,
Cholesky, QR, SVD, Schur, generalized Schur) are also provided, as are
related computations such as reordering of the Schur factorizations
and estimating condition numbers. Dense and banded matrices are
handled, but not general sparse matrices. In all areas, similar
functionality is provided for real and complex matrices, in both
single and double precision.

This package contains the Fortran 77 reference implementation of BLAS
and LAPACK from Netlib. The C wrappers CBLAS and LAPACKE are provided
in separate packages.

Homepage:
https://www.netlib.org/lapack/
