> An ideal might be if, as the author falsely claims, apps actually were structured as CLI or APIs overlaid with a GUI. You could then program the CLI/API layer

> An ideal might be if, as the author falsely claims, apps actually were structured as CLI or APIs overlaid with a GUI. You could then program the CLI/API layer, or re-configure or even re-write the GUI layer to taste. I also thought of like that (although the command-line and GUI are both done from the API; some parts can be done automatically but some parts must be programmed explicitly), it would work better that way. (It is one of the things that I had considered with operating system design.) However, there are details to be considered, such as the usual considerations of CLI, API, GUI, and how these things would be done in order to work well together (I had considered some such details too, though). Of course it would allow to reconfigure and rewrite the GUI layers, which is an advantage; it would also have many other advantages if this mechanism is designed well.