exo-notify contains the exo-mount-notify binary that is created when 
compiling exo against libnotify. All other exo files are included in 
the official Slackware Xfce package.  Note that the version of exo
used to build exo-notify must match the version of exo included with
the Slackware's xfce package.

libnotify is required to build exo-notify.