The following compilers and
most of their extensions
are supported:

IBM VS Fortran V2
VAX Fortran
DEC Fortran
DEC PDP-11 Fortran
Prime Fortran
Cray CFT77 Fortran
Convex Fortran
Cyber Fortran NOS/VE
Unisys 1100 Fortran 77
Apollo/Domain Fortran
Sun F77 Fortran
HP Fortran/9000
HP Fortran 77
Control Data 4000 Fortran
Silicon Graphics Fortran 77
IBM RS/6000 AIX XL Fortran
Microsoft Fortran
Microsoft Fortran Powerstation
RM/Fortran
IBM Professional Fortran
Lahey F77L
Digital Research Fortran-77
Prospero Fortran
Salford FTN77/386 Fortran
WATCOM Fortran 77