Since the Imake mechanism doesn't currently seem to work properly
for RCS, we've included a Makefile created by Prof. Franklin of
ECSE for his Computer Graphics course.  If your program is all in
one source file, it will work directly.  If not, modify the two
lines reproduced below so that your program name and ".o" filenames
are correct:

vend:     vend.o callbacks.o
        $(CC) $(CPPFLAGS) $(LDFLAGS) -o $@ vend.o callbacks.o $(LDLIBS)