What does HackerNews think of emacs-ng?
A new approach to Emacs - Including TypeScript, Threading, Async I/O, and WebRender.
undo-redo is in emacs-28 now, though not the default behavior.
> Allow writing Emacs commands in popular languages like Python 3 or JavaScript.
For js see https://github.com/emacs-ng/emacs-ng
Integrating additional runtimes into the Emacs core, especially ones that also have a single main thread are likely to be a complete nightmare. There are already insane and undebugable performance issues with things that run on the main graphics event loop or on timers.
If elisp can somehow be made multi-threaded there might be a chance. However, there is SO much elisp code that assumes synchronous ordered execution that will break in subtle and unexpected ways when that restriction is lifted I expect it will take even longer than the transition to lexical scoping (and that is just in the core). I would love to be wrong though.
With respect to Python, the cpython runtime and semantics for redefinition are likely even more nighmareish because it is so easy for classes and instances to become out of sync and you wind up having to restart the whole environment just to clear out the bad state or risk creeping insanity. Also the churn in the Python ecosystem is likely far too high for Emacs to be able to maintain. So there are both technical and process mismatches. You could always run python in a separate process and use message passing though. Work to support LSP certainly paves the way for it, and elpy has fully interop with python as well, so you could use that machinery to operate on buffers in languages beyond python. So if all this is possible why isn't anyone doing it?
No affiliation and haven’t even used it - but it seems to have legs.
[0] https://github.com/emacs-ng/emacs-ng Disclosure I've posted about this on HN in the past, but I felt it was very relevant to the parent comment.
However, I do agree with you that Emacs onboarding process can be difficult if you don't know lisp, in that you have to now learn a new language and the API for interacting with the editor. That is why some friends and I recently decided to embed JavaScript/TypeScript into Emacs as a means of controlling the editor [1]. We will see if we can prove you right.