> Obviously Fortran is used a lot in HPC and numerical routines, but I always figured those were closed-source and rarely updated, with development focusing on

> Obviously Fortran is used a lot in HPC and numerical routines, but I always figured those were closed-source and rarely updated, with development focusing on their wrappers. There are quite a few that are open-source, and often under very permissible licenses, even public domain, because they were developed under university research programs. I remember finding at least half a dozen, if not more, open high-performance libraries that implemented a direct method for solving sparse linear systems. I'm fairly sure that applies to most everything else.