Denis, I think you will need to do is figure out where libX11.a and libX11.so live. It's probably in /usr/X**/lib/libX11.a -- that is, there is probably some X windows directory under /usr, it may be 'X11', 'X11R6', 'Xorg', .... or something. Once you find this, you have a few options: you could edit the makefile generated by PGPLOT_install or do a more manual install of PGPLOT. A simpler approach would be to make a symbolic link so that '/usr/X11R6/lib/' was the directory for libX11.a and libX11.so, probably something like ln -s /usr/Xorg /usr/X11R6 and then PGPLOT_install should work as is. Please let me know what you find. Right now, PGPLOT_install looks for '/usr/X11' and '/usr/X11R6' and for the 64bit variations. It would not be hard to add other locations. --Matt