Now, a bit of experience of mine. I did compile and run the graphical shell on Cygwin (in the X Window mode), and even got to the main program screen, but did something wrong, and the climate run was aborted abruptly. So, all things considered, mastering this would require a bit of time, and also motivation. Maybe if I go into planetary development...
Cygwin is the easiest way to run this model, just be sure to install GNU FORTRAN and the tcsh package. The configure.sh script may need tweaking to ensure that FORTRAN and C compilers match.