A Firefox extension that changes a value in the about:config

Question

I\'ve been searching far and wide through the web for some tiny bit of light, but found nothing. I need to create a Firefox extension that, among a few other things, changes

Answer 1

Firefox 57 and newer (WebExtensions)

Not possible, details in Is it possible to create a Firefox WebExtension that changes about:config settings? How?

Old Firefox (legacy extensions)

The about:config values are accessed via the preferences system. The reason you preface your extension's prefs with extensions.myextension is because you need to make sure you don't collide with Firefox's or another extension's preferences.

To get a firefox preference just use the same preference name as you see in about:config. If you notice, you'll see that you also see all of the extension prefs in about:config too.

https://developer.mozilla.org/en/XUL_School/Handling_Preferences * https://developer.mozilla.org/en/Code_snippets/Preferences