http://en.citizendium.org/wiki/Unix_directory_structure http://en.citizendium.org/wiki/Unix_directory_structure /usr -- originally the directory holding user h

http://en.citizendium.org/wiki/Unix_directory_structure http://en.citizendium.org/wiki/Unix_directory_structure /usr -- originally the directory holding user home directories, its use has changed, and it now holds executables, libraries, and shared resources that are not system critical: X11, KDE, PERL, etc. (The name "Unix System Resources" is a post hoc backronym.)