This is the most popular open-source choice. It is part of the GNU Compiler Collection (GCC) and fully supports Fortran 77 alongside modern standards. How to Get It : You can download it through , which provides a 64-bit environment for Windows.
For 99% of users looking to run Fortran 77 on Windows 10: fortran 77 compiler for windows 10 64-bit free download
Recommendation: Use gfortran (GCC) via a packaged Windows distribution (MSYS2, MinGW-w64, or TDM-GCC) or via Windows Subsystem for Linux (WSL). This gives the best combination of compatibility, support, tooling, and active maintenance. This is the most popular open-source choice
is the most widely used free, open-source compiler. It is part of the GNU Compiler Collection (GCC) and fully supports Fortran 77, 90, 95, 2003, and 2008 standards. Fortran-lang How to Download to get the 64-bit Windows version. Installation Tip : For easy setup, download the MinGW-w64 installer and ensure you select the For 99% of users looking to run Fortran
It is technically a paid product, but it offers a fully functional free trial and a "Legacy" version that often suits F77 needs perfectly. It is the closest experience to the old "PowerStation" or "Compaq" compilers of the 90s. 3. Silverfrost FTN95