self reply

upd

What's upd? Upd is yet another process/service monitor (like systemd, sysvinit, procd etc) but the difference between this one and all the rest is that it's substantially written in Fennel (a Lua-based Clojure-ish Lisp dialect)

The name is

  • an acronym for "micro process daemon", or
  • a shortened form of "up daemon", because it brings things up

I prefer the second explanation. Technically it's not a daemon, but also technically systemd is not a daemon (does it fork into the background and then exit? Nope) either and nobody complains about that do they?