Not a useful note and more of a personal opinion then factual, but beyond the inventors of the Internet or any hardware has to be the following notion from IBM:
Source: Behavioral Issues in the Use of Interactive Systems.
If you've guessed it, my vote goes for whoever invented the "Undo" button: cross-platform, multi-lingual, future-proof and as everlasting as human error.
"By [undoing] repeatedly, you can gradually work your way back to a point before your mistake. This is convenient if you've made a mistake four or five commands back. It is marginally useful if you've made a mistake twenty or thirty characters back. And it is completely useless if your mistake is ancient history." - Learning GNU Emacs (page 42)
Undoing can itself be undone. After having undone an action, you can redo it... - Docs.Gimp.Org
Latin - Etymology - From unda ("a wave")