dspgv(3) on Linux
The text cb8f4da37ea3, as Debian 4.0 (Etch) shipped it.
compute all the eigenvalues and, optionally, the eigenvectors of a real generalized symmetric-definite eigenproblem, of the form A*x=(lambda)*B*x, A*Bx=(lambda)*x, or B*A*x=(lambda)*x