Worked great until Mozilla changed the panic-quit command from Ctrl+Q to Ctrl+Shift+Q, which I've accidentally mashed, so this extension no longer does anything. (Experienced in Firefox 62.0.2, Windows 7, 64-bit.)

it doesn't work

Works flawlessly on MacOS.
Would you mind publishing the source code? A GitHub repo would be great.

Doesn't work on Ubuntu!

doesnt work

STILL does not work on Linux.

It doesn't work. At all.

Does not work (Firefox 61.0.1 on Linux).

July 12 2018, still not wrrking for linux

This addon does not work. It allows ctrl+q and cmd+q to both close Firefox.

It doesn't work at all. I'm running Firefox 62 on Debian Stretch with Gnome.

Edit:
I'd like to apologize as I just now realized that the description says the extension doesn't work for Linux. Apparently there doesn't seem to be a way to delete my review, so I'm changing my rating from 1 star to 3 which I consider neutral.

I used to take advantage, before FF Quantum, of the great "Warn before quit" plugin, that was much more comfortable: you were simply prompted to press CMD-Q again if you were sure of quitting.
Here it's to basic to just disable CMD-Q! At least, there should be the option to quit otherwise, for instance by Alt-Q or whatever else.

You had one job
(Ubuntu 18.04, FF60)

Best. Add-on. Ever. It's as simple as that. Windows 10 user.

Does not work on Ubuntu w/ FF 60.0

This extension saved my life. An essential download; cmd-q and cmd-w are just one key away from disaster!

Essential addon for FF, unfortunately not working in Ubuntu

Still not working on linux based systems.

Works great on Windows 10, my only gripe is that you can't configure the hotkey, because I commonly use Ctrl-tab and Ctrl-shift-tab to change tabs and find myself accidentally hitting q at the same time.

Works perfectly on Windows and OS X, but sadly doesn't work on Linux. However, this is clearly stated in the description, so no false promises - thus 5 stars.

Excellent add on. Not sure why this still isn't a feature! Really appreciate Rob W making this.

Doesn't work

Doesn't work: firefox exiting

Worked well, now it's defunct.