CORSIKA, current Version 7, is a program to simulate extensive air showers, ie particle physics in the atmosphere. It's main file is 88kloc Fortran 77, started

CORSIKA, current Version 7, is a program to simulate extensive air showers, ie particle physics in the atmosphere. It's main file is 88kloc Fortran 77, started in the eighties, still actively developed. https://www.iap.kit.edu/corsika/index.php https://www.iap.kit.edu/corsika/index.php Currently a rewrite in c++ is underway.