Automake includes full support for Fortran 77.
Any package including Fortran 77 code must define the output variable
F77 in configure.ac; the simplest way to do this is to use
AC_PROG_F77 macro (see Particular Program Checks).
A few additional variables are defined when a Fortran 77 source file is seen:
Automake can handle preprocessing Fortran 77 and Ratfor source files in addition to compiling them1. Automake also contains some support for creating programs and shared libraries that are a mixture of Fortran 77 and other languages (see Mixing Fortran 77 With C and C++).
These issues are covered in the following sections.