güzel

Que no necesito esperar lo molestos 5 segundos, pero me gustaria que fuera compatible con las versiones de mozilla firefox mas antiguas desde la version 50.0.1

Good

If you are searching for an alternative, choose ViolentMonkey, it's also open source.

jQuery not to work

I like you because make my job succes

The old version was FANTASTIC!!

The new version doesn't work with my 3.17 scripts.
GM >=4 can't read scripts from the filesystem. So crap. So you have to use the crappy GM>=4 code editor.
The new GM also can't seem to access window variables, I can't be bothered to figure out why because I wouldn't want to use the GM4.x code editor. The Violentmonkey workaround I found online of serving the script from a local webserver sucks. It's a stupid and useless pain.

WTH!!!!!!!!!!!
This is the worst update EVER!!!!!
GM >=4 sucks and I'm sticking to 3.17.

If you want to run GM 3.17 this is what you need:
extract
https://download-installer.cdn.mozilla.net/pub/firefox/releases/56.0.2/linux-x86_64/en-ZA/firefox-56.0.2.tar.bz2
to /opt

run it like this
nohup /opt/firefox-56.0.2/firefox --no-remote -P foobar-profile 'http://foobar.com/' >/dev/null 2>&1 &

Go to preferences tell firefox to never update.

Disable GM 3.17 update
about:config
make new false boolean value named
extensions.{e4a8a97b-f2ed-450b-b12d-ee082ba24781}.update.enabled

Install GM 3.17
https://addons.mozilla.org/en-US/firefox/addon/greasemonkey/versions/?page=1#version-3.17

Muito bom
D÷