The Linear Algebra PACKage (LAPACK) is a library of numerical solvers for dense linear algebra problems. It provides routines for solving systems of linear equations and linear least squares, eigenvalue problems, and singular value decomposition. Similar to BLAS, LAPACK routines are implemented in various libraries, including MKL and ATLAS for Linux systems and ESSL for CORAL systems. For additional information, consult the LAPACK website.