Not sure, but I can tell you that Emacs is weird inside, in a lot of ways. It runs an interpreter for a language that nobody else uses, which has been heavily

Not sure, but I can tell you that Emacs is weird inside, in a lot of ways. It runs an interpreter for a language that nobody else uses, which has been heavily optimized because otherwise Emacs would be too slow. Then they use tricks to speed up executable loading, like loading Emacs and then writing the contents of memory to disk, so it can be loaded more quickly the next time.