sspgv(3) on Linux
The text 1f8c398a4f4e, as Debian 3.1 (Sarge) 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