It has been a few years, but less than 10 years ago I worked on a small project where we used the Intel FORTRAN Compiler: https://software.intel.com/content/www

It has been a few years, but less than 10 years ago I worked on a small project where we used the Intel FORTRAN Compiler: https://software.intel.com/content/www/us/en/develop/tools/oneapi/components/fortran-compiler.html https://software.intel.com/content/www/us/en/develop/tools/o... It's well maintained and highly optimized. Before then, I had not used FORTRAN since 1983 (and it was old even then).