Levee is a screen oriented editor based on the Unix editor "vi". It provides a terse, powerful way to enter and edit text (however, if
you want a word-processor, you're better off with WordStar.)
Levee is a moded editor. It operates in 3 modes -- visual, command,
and insert. Most of the editing work is done is visual mode, file
reading and writing is done in command mode, and insert mode does
what you would expect.
https://www.youtube.com/watch?v=sjC1YqjQ5bs