People also have this false preconception that you have to write everything in Fortran77. You can keep a F77 codebase alive, while writing Fortran 90 (0) code which is surprisingly modern, has amazing mathematical computational performance (especially with Intel&#x27;s MKL and compiler), and the language has amazing OpenMP integration.<p>I&#x27;m with you on combining the best tool for the job and sometimes having a Java&#x2F;C&#x2F;Python wrapper is useful, but you can retain your Fortran tried-and-true-and-tested code-base while adding feature enhancements compiling against the Fortran2003 standard and often eliminate the need for wrappers. I guess the practical problem is finding F2003 engineers is way more challenging than a Java or C# dev.<p>0: F90 was the &quot;big&quot; upgrade that came out which made Fortran  &quot;modern&quot;, but there have been continuous upgrades like F95, and Fortran 2003 (I guess this would be analogous to C++17) which make it perfectly fine to write.