Modern Fortran is still popular for computationally-heavy economics. C and C++ never really caught on because it's irrational to use one of those languages when

Modern Fortran is still popular for computationally-heavy economics. C and C++ never really caught on because it's irrational to use one of those languages when Fortran will do. Julia, on the other hand, is now gaining ground because it's both fast and usable by humans.