FORTRAN

Actually, FORTRAN isn't always used on "antiquated systems". It's quite the opposite in a number of cases, it's one of the language of choice for stuff designed to run on supercomputers. The main reason for this, and likely one of the reason it is kept in academia, is that the structure used by FORTRAN allows a bit more optimization at compile time than, say, C does. For most applications you don't really care enough about the performance hit, so it's not worth it to use a less flexible language just to remove 10 instructions in a loop. However, spending an additional week on your program because of FORTRAN isn't that bad if you're going to remove a month worth of computing time on a cluster of giant machines.

Jam it back in, in the dark.