Gfortran is the GNU Fortran 95 compiler front end, designed initially as a free replacement for, or alternative to, the unix f95 command; gfortran is command you'll use to invoke the compiler.
Gfortran is not yet a fully conformant Fortran 95 compiler. It can generate code for most constructs and expressions, but work remains to be done. In particular, there are known deficiencies with ENTRY, NAMELIST, and sophisticated use of MODULES, POINTERS and DERIVED TYPES. For those whose Fortran codes conform to either the Fortran 77 standard or the GNU Fortran 77 language, we recommend to use g77 from GCC 3.4. We recommend that distributors continue to provide packages of g77-3.4 until we announce that gfortran fully replaces g77. The gfortran developers welcome any feedback on user experience with gfortran at firstname.lastname@example.org.
When gfortran is finished, it will do everything you expect from any decent compiler:
The compiler will also attempt to diagnose cases where the user's program contains a correct usage of the language, but instructs the computer to do something questionable. This kind of diagnostics message is called a warning message.
Gfortran consists of several components: