Best for: Most users, open-source, standard-compliant, active development.
What is it?
gFortran is part of GCC (GNU Compiler Collection). It supports Fortran 77, 90, 95, 2003, and later. It’s free, battle-tested, and works perfectly on Windows 10 64-bit.
Download & Install Steps:
Run installer
Add to PATH
Verify install
Compile a Fortran 77 program:
gfortran -std=legacy hello.f -o hello.exe
Open a Command Prompt or PowerShell and type:
gfortran --version
You should see something like:
GNU Fortran (MinGW-W64) 13.2.0
Copyright (C) 2023 Free Software Foundation, Inc.
If you see an error, restart your terminal or check your PATH.
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.
Verify installation: Open Command Prompt (or PowerShell) and type:
gfortran --version
You should see output like GNU Fortran (x86_64-posix-seh-rev0) 8.1.0. fortran 77 compiler for windows 10 64-bit free download
| Compiler | 64-bit native? | IDE included? | Best for | |---------------------|----------------|---------------|--------------------------------| | gFortran (MinGW-w64) | Yes | No (use VS Code/Notepad++) | Production, standards | | Silverfrost FTN77 | No (32-bit) | Yes (Plato) | Learning, quick testing | | MSYS2 + gFortran | Yes | No | Unix-style development |
Q: "gfortran is not recognized"
A: You forgot to add the bin folder to PATH. Recheck Environment Variables.
Q: FTN77 crashes or won't install
A: Run installer in Windows 7 compatibility mode (right-click → Properties → Compatibility).
Q: My Fortran 77 code uses non-standard extensions
A: Use gfortran -std=legacy to accept old syntax. Run installer
Q: Need a full IDE with debugging
A: Install Code::Blocks with gFortran or Simply Fortran (commercial but trial available).