This is a short demo of the fortran support in libtool.

fprogram is a pure-fortran program which is linked 
against the fortran-only library libfoo.la

cprogram is a C program, which is linked against the
mixed C and fortran library libmix.la. The program
calls a C function, which in turn calls a fortran 
function.

This demo requires GNU autoconf, automake, 
libtool with the F77 tag and quite obvious Fortran 77.