His own emacs mode (https://bellard.org/qemacs) I don’t think he uses it anymore but I always found that the best side effect of concise/elegant (minimal) code (or perhaps goals/scope) is generally better performance (I think this is also partly because of a single author understanding a lot more of a ‘product’ than a team)

Also wanna throw Mike Pall & Arthur Whitney in there as an honourable mentions (productive gods/100x)