wrt to old crusty FORTRAN code: scipy is using many of those popular libraries, it is based on them.

wrt to type signatures, many of those ancient FORTRAN libraries are written with implicit interfaces, so bugs are likely to show up. I came to learn this when compared some versions floating around with the patched versions supplied with scipy.

My aim is not to bash, but justify scipy is a solid piece of software, based on known developments, not just a shiny "new" thing.