Because GLUT fonts are compiled directly into GLUT programs as data, and programs should only have the fonts compiled into them that they use, GLUT font names like GLUT_BITMAP_TIMES_ROMAN_24 are really symbols so the linker should only pull in used fonts.
Unfortunately, because some supposedly modern FORTRAN compilers link declared but unused data EXTERNALs, ``GL/fglut.h'' does not explicitly declare EXTERNAL the GLUT font symbols. Declaring the GLUT font symbols as EXTERNAL risks forcing every GLUT FORTRAN \ program to contain the data for every GLUT font. GLUT Fortran programmers should explicitly declare EXTERNAL the GLUT fonts they use. Example:
SUBROUTINE PRINTA
#include "GL/fglut.h"
EXTERNAL GLUT_BITMAP_TIMES_ROMAN_24
CALL glutBitmapCharacter(GLUT_BITMAP_TIMES_ROMAN_24, 65)
END