Grapically displays the amount of disks used for by each subdirectory
xdiskusage is a user-friendly program to show you what is using
up all your disk space. It is based on the design of xdu
written by Phillip C. Dykstra. Changes have been made so it runs
"du" for you, and can display the free space left on the disk,
and produce a PostScript version of the display.