And also the author of the ledger CLI accounting tool: https://www.ledger-cli.org

Extremely knowledgeable and warm person on top of that. He's the genuine next level.

If I am not mistaken, Emacs maintainance has been passed on to Lars (the author of Gnus). In any case, John is a great person involved in a lot of interesting free software. He conceived ledger (a cli double-accounting tool) and wrote a lot of emacs packages, amongst other things. Big Up to johnw!