[jiehong]

The closest thing we've had might be Lisp Machines, but that didn't work out.

That's why Emacs is still great: users can do whatever they want with it, and they do.

To a lower degree, we can sort of do that with workflow engines on the cloud (ex: Azure Logic Apps), or locally (ex: iOS Shortcuts).

As a user, I like being able to do that, but I do not like having to maintain my partially working thing, nor do I want to spend time ensuring it works as I expect (aka doing QA) outside of what I use it for today.

[izuchukwu]

A big issue there is accessibility to a broader audience—something that Emacs and Lisp Machines don't quite have. Like you said, iOS Shortcuts is a very interesting example. You could say Internet-native automation tools like Zapier and Integromat fit the bill here too.

I wouldn't see potential maintenance or QA work as a deterrent to mainstream adoption. Users would underestimate it just like developers today do.