And it doesn't say which Fortran they are using bog standard GFortran or Intel Fortran with all the parallel extensions.
With this sort of code you also tune it to the machine architecture back when I did F77 for BT / Dialcom the code was tweaked to suit the PR!ME Architecture to get extra speed
when they say 'modern' fortran i take it to imply a a compiler and standard from sometime in the last 20 years.
i've heard people refer to c90 as modern before.. (in the last two years) and the nasa/astronomy guys are famously clingy to 'known good' tech from the olden days.
only the very most recent astronomical dataset i acquired was in .csv. everything is made for fortran from what i've seen over the last 10 years...
With this sort of code you also tune it to the machine architecture back when I did F77 for BT / Dialcom the code was tweaked to suit the PR!ME Architecture to get extra speed