There is a plan9 and acme demo on YouTube which is eye opening. One idea that has captured me is the idea that end users ought to be able to create custom UIs. This appears to be a foundational principle of plan9, the way all text is able to be executed. Another avenue for this idea are ZUIs as originally envisioned. Individual clipboard state can be reified as buttons in the UI, any formatting or pens or fonts can also be manifested in the interface and selected with something along the lines of the "eyedropper" tool present in many applications.
I agree, thanks for pointing me to that info page. I would bet that keys representing functions probably evolved simultaneously with the first computer typewriters, they've been around forever and are "obvious" to some degree. Making functions apparent in menus is also probably synonymous with the first non text-based GUIs. I don't know enough about the history of toolkits, but as far as I can tell that area of development is nowhere near mainstream today.
I have been reading Sutherland's Sketchpad thesis, and it struck me that no aspect of the system was unavailable to the user. By itself, this isn't entirely unusual, I think the same could be argued for emacs or linux in various ways or even of software when code is available etc. The unique aspect of this universal control with regard to sketchpad is that it was a graphical system. Controls for the graphics and viewport were essential, and reflected by the development of the first oop principles of master/instance and recursive expansion of arbitrary material in the workspace. Of multiple viewport movement controls (physical dials too!) and focus-selection zooming.
It is easy to imagine extensions of sketchpad with graphical macros. Of savable viewport state, of non-euclidean jumps between locations on the digital "paper".
It's funny to me that most clever things I enjoy about vim seem like they could fit right into a graphical system like sketchpad. `mkview`, marks, folds, repeat operations, contextual movement or selection like accessed via combinations of `[{(`.
Infinite canvas artboards are fantastic workspaces, but lack even the basic "focus shifting ability" of a few stacks of paper on a desk, taped on a wall, or strewn across the floor.
The thing I like about the best parts of vim and emacs is how much it feels like a conversation with the computer. Such that it natural lends itself to interacting with completed things. Indeed, "ciw" only works if you have a completed "word" to change.
Notebooks are usually tons and tons of fragments. Such that a precise dialog with them feels very difficult. I agree it would be awesome, but I have yet to see something that doesn't just harken to the ultimate failures of graphical programming languages. Neat for performance style programming. But needing a ton of rehearsal to get a performance.
edit: video here https://www.youtube.com/watch?v=dP1xVpMPn8M "A Tour of the Acme Editor" by Russ Cox