The recent flurry of activity with neovim have made me wonder if there could be something similar for the other editor, emacs.
If you poke around recent GNU Emacs releases you'll come across random signs that the code carries a lot of baggage:
There are special considerations for a variety of this system which is known as the ``Yellow Dog [GNU/]Linux'
Yellow Dog [GNU/]Linux has been dead for many years now.
Contains references to skipping stuff that runs under Emacs 19, 20, 21, & 22.
None of these are huge things, and the core code of Emacs is a pleasure to read in many places, but it does make you think, or not, whichever the case may be it is all good :)
(I do all "real work" in emacs. I write all outgoing emails in vim, and use it for git/mercurial commit messsages, otherwise the only time I use it is for random one-line edits over slow links.)