Even if you don’t obsess over Emacs like, ahem, some people, you’ve probably heard about the project to compile Elisp to native code. The idea is that the Elisp byte code would be compiled to GCC IR (intermediate representation) code and then fed to GCC to compile into native code for whatever platform Emacs is running on. This has exciting implications for Emacs’ performance, of course, but it also opens the possibility of replacing some of the C code with Elisp.
Andrea Corallo gave a talk on the project at the 2020 European Lisp Symposium that discusses how the compilation works and where they are right now. It’s currently a feature branch on the Emacs git repository. This is definitely an exciting development for Emacs end users and developers alike. I’ve been trying to maintain my composure about this project in case it fizzled out but now it appears to be a real thing and perhaps we’ll see it appear in Emacs as soon as Emacs 28.
Corallo’s talk is interesting and well worth watching. It’s just short of 27 and a half minutes so you’ll have to put some time aside. The slides for the talk are also available so don’t worry about trying to absorb everything on them during the talk.