Everywhere in computers you see hierarchies.

If they're everywhere, then invest in a tool that edits and displays hierarchies really well.

Jack up the UI of the system, and get the editor/displayer deep in the OS, underneath everything.

And make everything everywhere editable or viewable with the hierarchy editor.

And hierarchy editor is just another term for outliner.

Voila!

PS: If you want to try one, check out littleoutliner.com.