[afc]

> Something I have wanted to create for a long time (definitely more than 5 years) is a new modal editor. I don't want yet another vi clone: I want something that is defined from the ground up by user configuration.

This is more or less the philosophy of the editor I've been working on (and using ~exclusively) since 2014: https://github.com/alefore/edge/tree/master

Some parts of the UI are still defined in the compiled language (so don't fully fit your philosophy yet), but a big part of the UI comes from the configuration loaded at runtime: every time the editor starts, it interpretes and runs this configuration defining the UI: https://github.com/alefore/edge/blob/master/rc/hooks/start.c...

(This file is not compiled into the editor, but loaded and executed directly at runtime; the format of that file is my editor's extension language/configuration (the equivalent to emacs lisp or vimscript), which just happens to be a garbage collected C-like language.)