fpp is a Fortran preprocessor for FORTRAN 77 and Fortran 90 programs.

Historically, the source code preprocessor found in standard C compilers,
cpp, has been used to provide Fortran programmers with preprocessing
capabilities.  However, cpp is too closely tied into the C language syntax
and source line format to be used without careful scrutiny.  The proposed
Fortran PreProcessor, fpp, would provide Fortran-specific source code
capabilities that C programmers have come to expect in UNIX environments.

WWW: http://netlib.org/fortran/