Since the question was "Ctrl-z works universally", I feel obliged to point out that ctrl-z sends SIGTSTP, which can be blocked--not to be confused with SIGSTOP, which cannot be blocked. I don't know of any program that does intercept SIGTSTP (except a test program I wrote that tries to print the name of any signal it receives), and I suspect that "polite" interception would be to release a few resources and then accept being paused--but, in theory, a program could ignore it.

This is probably a stupid question, didn't know about bg and fg before. But after playing around with it, it feels pretty amazing, why even use screen/tmux when you have these?

With bg, it is likely to suspend itself again by attempting to read from the terminal (which a text editor is likely to do basically all the time).

If you have good reflexes, you can type "^Z" right after "kill -9", before the syscall to send the signal is executed.

Legend has it that, if you do, you bring on the Singularity immediately.

There is no reason for -9 here - all the major unix editors happily exit on SIGTERM.

My vimrc has

    source $VIMRUNTIME/mswin.vim
    behave mswin

which maps Ctrl-z to undo.

Well I'll be damned. Never thought of trying it. Thank you.

Ha, I still do that!

    $ jobs
    [4]   Stopped                 emacsclient -a '' -nw [redacted]  (wd: [redacted])
    [5]   Stopped                 emacsclient -a '' -nw [redacted]  (wd: [redacted])
    [6]   Stopped                 emacsclient -a '' -nw [redacted]  (wd: [redacted])
    [7]   Stopped                 emacsclient -a '' -nw [redacted]  (wd: [redacted])
    [8]   Stopped                 emacsclient -a '' -nw [redacted]  (wd: [redacted])
    [9]   Stopped                 emacsclient -a '' -nw [redacted]  (wd: [redacted])
    [10]   Stopped                 emacsclient -a '' -nw [redacted]  (wd: [redacted])
    [11]   Stopped                 emacsclient -a '' -nw [redacted]  (wd: [redacted])
    [12]-  Stopped                 emacsclient -a '' -nw [redacted]  (wd: [redacted])
    [13]+  Stopped                 emacsclient -a '' -nw [redacted]

But since they're all emacsclients it doesn't really matter.