ARPACK - Package for large-scale eigenvalue problems. EISPACK - A collection of Fortran subroutines that compute the eigenvalues and eigenvectors of nine classes of matrices: complex general, complex Hermitian, real general, real symmetric, real symmetric banded, real symmetric tridiagonal, special real tridiagonal, generalized real, and generalized real symmetric matices. In addition, two routines are included that use singular value decomposition to solve certain least-squares problems. Lanczos - Codes to compute eigenvalues and eigenvectors using the Lanczos algorithm. Lanz - Solves the large, sparse, symmetric generalized eigenproblem. Laso - Fortran IV subroutines for computing a few eigenvalues of a large (sparse) symmetric matrix. SLEIGN2 - Code to compute eigenvalues and eigenfunctions of regular and singular self-adjoint Sturm-Liouville problems.