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The Great Migrations FORTRAN to C Translator (gmFortran) is a tool that translates FORTRAN source code to correct (compilable) and clean (readable and maintainable) C source code. The C code produced can then be compiled with almost any C compiler on almost any platform to produce executable code, which in turn will produce results on the target C platform that are identical to the results produced on the source FORTRAN platform. What’s more, the C code is clean and readable so that, if you wish, you can start maintaining your application in C rather than in FORTRAN. And, unlike the original FORTRAN, the C code is portable so you can move it to multiple "open" platforms. In addition, the tool is flexible and configurable to allow extensive user control over both the input FORTRAN dialect accepted and the look of the C output generated.
This tool is intended for those who wish to convert their FORTRAN codes to C automatically; 100 percent conversion rates are achieved routinely. The conversions yield reproducible results and are repeatable and verifiable. A number of input FORTRAN dialects are supported via a dialect definition flag, and the form of the output C code is controlled by a multitude of command-line switches.
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“FORTRAN to C: Character Manipulation," Fred K. Goodman, Vol. 2, September, 1990.