Prebuilt EISPACK libraries are provided for a variety of architectures. http://www.netlib.org/eispack/archives/ NOTE: These EISPACK archives DO NOT contain the BLAS. For optimal performance, please use the vendor-optimized BLAS library for your architecture. If such a library is not available, you can download a prebuilt reference implementation Fortran 77 BLAS library http://www.netlib.org/blas/archives/ or you can download the source code from http://www.netlib.org/blas/blas.tgz The EISPACK source code is available from the following URL: http://www.netlib.org/eispack/ Questions/comments should be directed to lapack@cs.utk.edu.