There are lots of applications written on top of GNU Emacs, but most of the time they use the specific UI and features of an editor, or integrate with the edito

There are lots of applications written on top of GNU Emacs, but most of the time they use the specific UI and features of an editor, or integrate with the editor. Example: the calculator of GNU Emacs. https://www.gnu.org/software/emacs/manual/html_mono/calc.html https://www.gnu.org/software/emacs/manual/html_mono/calc.htm...