Edit: Emacs is a great example btw. It is single threaded, and a lot of it is written in elisp, which is slow and makes emacs have noticeable lag if you turn so

Edit: Emacs is a great example btw. It is single threaded, and a lot of it is written in elisp, which is slow and makes emacs have noticeable lag if you turn some features on. The question was whether it was instant, rather than usable. ---------------------- First and foremost, atom has pretty much noticeable lag, even for someone like me who thinks emacs is instant (which it isn't). I agree that it requires a sensible plugin design, but the GIL will only get you so far. I haven't used atom much, but I suspect the heavier plugins rely on async tasks, which can be implemented using python's threads, or for python 3.4 and later using asyncio. This takes me to my next point: People also under-estimate how FRIGGIN FAST v8 is. JS executed in v8 (or node) will run so many laps around cpython it makes a web-technology-hater (but whatever floats your boat!) like myself cry and bang my head to the wall. People seem to think that they play in the same league. They do not.