Earlier quoted context omitted.
Emacs is definitely capable of multithreading. Still using a single thread might actually be a boon because it simplifies the programming model. Right now, Elisp code can work under the assumption that there is only one thread accessing editor state at the same time. Disentangling this is probably going to be difficult, but the Emacs folks are probably smart enough to come up with something that matches with the spir…
To outsource things step-by-step to lightweight processes seems to be a good incremental way to disentangle. Perhaps one could protect access to resources not initially invented by Emacs packages (Emacs core?) and make Emacs query a separate process, without a package knowing about that, so that it channels all communication to the separate process. Then deprecate directly the resource at some point and offering a mo…
In terms of the protocol itself, I suspect it’s actually worse than a lot of other ones.