>  cc -G -z defs -o libvis5d.so v5d_read.o v5d.o binio.o \
>  -lm -lc
>  cc: unrecognized option '-G'
>  /usr/lib/crt1.o(.text+0x18): undefind reference to 'main'
>  collect2: ld returned 1 exit status
>  make:  *** [libvis5d.so] Error
Try making the following changes:
  1) Change
        JAVAINCS = -I${JAVADIR}/include -I${JAVADIR}/include/solaris
     to
        JAVAINCS = -I${JAVADIR}/include -I${JAVADIR}/include/linux
  2) Change
        SHCFLAGS
     to
        SHCFLAGS = -fPIC -DPIC
  3) Change
        SHLDFLAGS = -G -z defs
     to
        SHLDFLAGS = -shared
I *think* those are the right flags for Linux, but I haven't been able
to test them (I don't have access to a Linux box.)
I spent some time today hacking on the Makefiles, so this will hopefully
be easier someday soon.