Pretty much just any system where you push out events, and they get picked up by any listeners subscribed to listen for those events.
Definitely sounds like it's worth me having a look at though, it would be nice to not have to make my own on projects if Unity has one that's robust.
Glad it worked for you!
Ah, okay, simple enough.
With UnityEvent, you can add listeners from the editor, complete with up to (I think) one static, unchangeable-at-runtime parameter. I've no idea if that's common (it is among replacements), but I know I love it to death~
(Actually, it's the very same thing the GUI system uses for buttons and the like. Maybe you knew that already....)
