I've been searching around the web for Fortran compilers for OS X, and have come up with a few (Absoft Pro Fortran, gcc with g77 from the Fink project, f2c and ADAPTOR).
Which one is the best? While free is always good, if the performance is significantly better with the Absoft compiler, it may justify the cost as the application is very computationally intensive and the Fortran code is responsible for the majority of the run time. FYI: The Fortran code is called, and has data passed to it, from a Java front-end, if that makes any difference.
Any help will be much appreciated. Cheers!