Let me just say that I use `raise SystemExit` all the time. Beats `from sys import exit`, weird error messages about having to type parentheses, and surely beats "oh, am I on Windows so Ctrl+Z, or on Linux so Ctrl+D". :-]

I also use `raise KeyboardInterrupt` sometimes in games, to test whether Ctrl+C handling works as expected at precise moments in the game (beats having to guess the millisecond in which to press Ctrl+C:).