Well, there was the shocking news here not long ago that some OS\360(?) backwards compatibility had been dropped. What's the world coming to.
Relevant to Fortran, there's a version of ESSL that I recall on OS\370 now for POWER9 (and doubtless 10). Scientific subroutine libraries are arguably the best example of the re-use beloved of those who haven't seen their OOP code last decades.
