On Mon, Nov 11, 2002 at 10:38:14PM +0100, Roman Joost wrote: [snip] > gcc lesson06.c -o lesson06 -L/usr/X11R6/lib -lGL -lGLU -lXxf86vm You probably need to add -lX11 for any X proggy (and maybe others). -- static const char signature[] = "Copyright (c) 2002 Eric G. Miller <egm2@jps.net>";