First please continue this discussion on COFF (which has been CC'ed).  While Fortran is interesting to many, it not a UNIX topic per say.

Also, as I have noted in other places, I work for Intel - these comments are my own and I'm not trying to sell you anything.  Just passing on 45+ years of programming experience.

On Mon, Feb 24, 2020 at 10:34 AM Adam Thornton <> wrote:
I would think that FORTRAN is likelier to be passed around as folk wisdom and ancient PIs (uh, Primary Investigators, not the detective kind) thrusting a dog-eared FORTRAN IV manual at their new grad students and snarling "RTFM!" than as actual college courses.
FWIW: I was at CMU last week recruiting.  Fortran, even at a leading CS place like CMU, is hardly "folk wisdom". All the science PhD's (Chem, Mat Sci, Bio, Physics) that I interviewed all knew and used Fortran (nad listed on their CV's) as their primary language for their science. 

As I've quipped before, Fortran pays my own (and a lot of other people's salaries in the industry).  Check out: Fortran is about 90% of the codes running (FWIW:  I have seen similar statistics from other large HPC sites - you'll need to poke).

While I do not write in it, I believe there are three reasons why these statistics are true and going to be true for a very long time:
  1. The math being used has not changed.  Just open up the codes and look at what they are doing.  You will find that they all are all solving systems of partial differential equations using linear algebra (-- see the movie:  "Hidden Figures").
  2. 50-75 years of data sets with know qualities and programs to work with them.  If you were able to replace the codes magically with something 'better' - (from MathLab to Julia or Python to Java) all their data would have to be requalified (it is like the QWERTY keyboard - that shipped sailed years ago).
  3. The scientists want to do their science for their work to get their degree or prize.   The computer and its programs are a tool for them look at data to do their science.   They don't care as long as they get their work done.

Besides Adam's mention of flang, there is, of course, gfortran; but there are also commerical compilers available for use:  Qualify for Free Software | Intel® Software  I believe PGI offers something similar, but I have not checked in a while.  Most 'production' codes use a real compiler like Intel, PGI or Cray's.

FWIW: the largest number of LLVM developers are at Intel now.  IMO, while flang is cute, it will be a toy for a while, as the LLVM IL really can not handle Fortran easily.  There is a huge project to put a number of the learnings from the DEC Gem compilers into LLVM and one piece is gutting the internal IL and making work for parallel architectures.  The >>hope<< by many of my peeps, (still unproven) is that at some point the FOSS world will produce a compiler as good a Gem or the current Intel icc/ifort set.  (Hence, Intel is forced to support 3 different compiler technologies internally in the technical languages group).