> I'd use "CLI" more precisely to refer to command-line invocation [...] For programs like vim or nano, I think "TUI" (text-based UI, or sometimes terminal UI)

> I'd use "CLI" more precisely to refer to command-line invocation [...] For programs like vim or nano, I think "TUI" (text-based UI, or sometimes terminal UI) is more suitable. Agree! I also consider that distinction but didn't think of it when writing. Luckily we knew we were talking about the same thing :) You're right about the GIMP example, but I think that just means that being a GUI program is not an automatic, free-pass guarantee to discoverability. GUIs make software capabilities more evident by the mere fact that they are there right in your line of sight, but of course it still needs a touch of good organization. But that becomes then a matter of visual design and information overload, which is a whole new area. TUI programs can be perfectly discoverable, as any well written Ncurses app can show. I don't use many, but the first one that comes to mind is Aptitude. You can just run it and, again, most if not all of the possible actions and settings of the program are right there in front of you to explore or notice.