WordGrinder
A word processor for the terminal, and the design reference for owlet.
WordGrinder is a terminal word processor described by its author as being built to “get the hell out of your way and let you get some work done.” That is very close to a mission statement I would have written myself.
owlet, the terminal half of Owl, is WordGrinder in feel: terminal-honest, not fighting the medium, not pretending a grid of cells is a canvas. The thing I took from it most directly is the attitude that a terminal application should be shaped by what terminals can actually do, rather than apologizing for the difference.
One concrete borrowing, since it’s a good example of the medium deciding: Ctrl+I is byte-identical to Tab in a terminal, so WordGrinder puts italic on Tab, on the grounds that prose doesn’t Tab-indent and the key is therefore free. Owlet did the same for a while, before the whole formatting tier moved onto Alt for consistency.