There seems to be a lot of influence between editors which to me is the most interesting part of all of this. Just looking at TKE's screenshots, it resembles VS Code to a not-insignificant degree, and VS Code and Atom both seem to have been inspired graphically by Light Table, and all of these as well as Alpha have a programmability that's heavily inspired by Emacs, although Alpha's GUI is closer to TextMate which was influenced by BB Edit, and the history of editors is something I'd love to see someone with more knowledge of the history do a more comprehensive write-up of it.