Since I work for a school of aeronautical and astronautical engineering and I'm thinking of making one of my compute servers linux based, I probably should really determine if g77 is good enough as a FORTRAN compiler.
I would think not. I talked with a grad student that uses linux and does a lot of FORTRAN work and she used PGI's compiler (Portland Group, Inc.). While it's not a good as Sun's compiler it seems to do a much better job than g77.
Oh well, I don't have the linux server yet so this is just idle chattering in my mind.