What Fortran compiler should I use?

G95, Gfortran, and Silverfrost (Windows only) are free Fortran 95 compilers, and Absoft, IBM, Intel, Lahey, NAG, Pathscale, PGI, and Sun sell Fortran compilers. Comparative information on Fortran compilers from Polyhedron Software is available at http://www.polyhedron.com/pb05.html