Installing a Fortran Compiler

Before writing any Fortran code, you need a compiler that turns your source file into an executable program. The most widely used free compiler is GNU Fortran, gfortran, part of the GNU Compiler Collection (GCC), and it is available on Windows, macOS, and Linux. Commercial alternatives like Intel's ifx and NVIDIA's nvfortran offer additional optimizations for specific hardware but are not required for learning the language.

On Windows, the simplest route is installing MSYS2 and then running pacman -S mingw-w64-x86_64-gcc-fortran, which gives you gfortran plus a Unix-like shell. On macOS, Homebrew makes installation a single command, brew install gcc, since gfortran ships as part of GCC. On most Linux distributions, gfortran is available directly through the system package manager, for example sudo apt install gfortran on Ubuntu or Debian, or sudo dnf install gcc-gfortran on Fedora.

Once installed, open a terminal and run gfortran --version to confirm the compiler is on your system PATH and check its version number. A successful install typically reports something like GNU Fortran (GCC) 13.2.0 or newer. If the command is not found, the installation directory likely was not added to your PATH environment variable, which is the most common setup issue beginners hit.