Despite being one of the oldest programming languages, Fortran is still one of the primary languages used for scientific and high-performance computing. The language has gone through seven major revisions since the original FORTRAN 66, with the latest standard being Fortran 2015.
There are several Fortran implementations available from commercial vendors, with the Intel Fortran compiler being one of the best in terms of producing highly optimized code. However, the Intel compiler costs about $300 per academic license, so for this class we will be using the freely available gFortran (aka GNU Fortran) compiler, which is part of the open source GNU Compiler Collection (GCC).
Installing gFortran
OS X:
Download the installer package from https://gcc.gnu.org/wiki/GFortranBinaries/
Make sure you follow the instructions in the file Readme.html that comes with the installer. You will need to install Apple's Xcode software and the Xcode command-line tools BEFORE installing gfortran (see instructions in the Readme.html file).
Linux:
Download and install the appropriate package for your Linux distribution. See https://gcc.gnu.org/wiki/GFortranDistros/
Windows:
In the Cygwin environment, download and install the gcc-fortran package.
Sample Code
program example
implicit none
integer :: i,j,k
real(8) :: x,y,z
i = 1
j = 2
k = i + j
write(*,*) 'k = ', k
! Comments in Fortran begin with a "!"
x = 1.8
y = 2.4
z = x + y ! this is another comment
write(*,*) 'z = ', z
end program