The commands `kill` and `pkill` are useful for more than just killing processes---they can send many different signals (see `kill -l`).
For example, I have `pkill -STOP icecat` and `pkill -CONT icecat` as i3 keybindings to pause and resume IceCat (a Firefox derivative), since most of the time I'm just working out of a terminal and don't need wasted battery. (Despite allowing JS only on my self-hosted Mastodon instance, it still uses more CPU than I'd like it to.)
@mikegerwitz SUGUSR1 sent to WindowMaker restarts it, often unwedging a wedged X11 session.
@mikegerwitz Solaris killall is best Korea.