[cm-t]

I agree, devtools are getting better. By the way , I recommmend developpers to use the developper edition https://www.mozilla.org/fr/firefox/developer/

[Someone1234]

Here's a generic link that should direct you to the page based on language (rather than the French or en-US one):

http://www.mozilla.org/firefox/developer/

[johnward]

What is the difference? I just thought it was basically a dark theme.

[addicted44]

They have some experimental features enabled there which they don't in other channels.

For example, I'm running Nightly, and the Dev Tools>What's New tab says the "Debug Variables with Watchpoints" (break when a property is read/written) feature is in Developer Edition (and presumably not in Nightly or the Release channel).

[sebazzz]

It is somewhat newer than mainstream, does not require to enter "yes I'm sure" when opening the dev console and has actually a beta qualifier as version number. I haven't run into any stability issues though.

[teknopurge]

I've been using the dev build for years. Highly recommended. (about:performance)