DevEdition is our fourth release channel, along with Stable, Beta, and Nightly builds. The engine is generally based on Beta, but we can ship features to DevEdition separately from mainline Firefox. For example, we can ship new developer tools to that channel before they land in Beta, it runs in its own separate profile by default, we allow Developer Edition to disable the add-on signing requirement, etc.

Apart from giving you access to all these features, being based on the beta also means that you can discover potential breakage in new Firefox versions before those hit the general public.

Hello Sir,

Pardon me if this is a silly question, but in the about:config page of Firefox Developer Edition the value for app.update.channel is aurora. But AFAIK, the aurora channel was stopped since April 18th of this month.

This is the screenshot : https://imgur.com/r5Kcqb3

Aurora used to be a separate pre-beta, post-nightly release channel:

    Release <--- Beta <--- Aurora <--- Nightly

In 2014, we rebranded Aurora builds to "Developer Edition" to give it better visibility and ship experimental features that we thought would be interesting to web and add-on developers.

Earlier this year, we sped up our time-to-release by removing Aurora from the pipeline, but we kept it as a separate channel roughly at parity with Beta:

    Release <--- Beta <--- Nightly
               Aurora <--'

Which is where things are today.

Thanks for the reply sir. I have one more question. I was very excited to use quantum, so ended up using developer edition. I am using it on my macOS High Sierra.

The battery usage and Energy impact that I observed from Activity Monitor application in macOS was very surprising.

Both parameters were quite high and the battery was draining very quickly. I don't have the screenshot. I tried searching for a solution like tinkering the about:config fields etc. but couldn't find any.

The aurora tree/part of the release cycle has gone away, but dev edition needs a separate update channel from beta, and was already using "aurora", so it was obviously less work to keep the name around just for the channel rather than rename it (and that might have prevented keeping existing dev edition users getting updates)

(So the _channel_ didn't actually ever go away, it just changed which tree it drew from)

(Tree being synonymous with "code repository" throughout this comment)

If you're a developer, use the developer edition, it's amazing. I'm too lazy to give you a feature-by-feature breakdown of what hasn't hit stable yet but... up until just recently "quantum" was one of them.

The news about FF getting faster is just hitting the mainstream now but developer edition has had it for months, and I haven't suffered any noticeable bleeding edge issues (mostly because I'm not on nightly). This might have to do with my update cadence with arch (firefox-developer is in the AUR) but I think more likely it's the distance from nightly.

Anecdotally I find it to be just the blind amount of "bleeding edge" (others described it well, behind nightly but ahead of stable), and I am now lost whenever I try to debug anything in chrome.

The developer edition is bit more bleeding edge than beta, but less than nightly. Nightly is updated daily. I'm not sure what the developer frequency is. But if your sporting it, you're getting the fresh features not entirely ready.

Isn't this incorrect? The developer edition appears to be built from the beta version. You get some alternate switches turned on, such as extensions no longer required to be signed & other stuff, but none of it is specifically new.

dark theme... and maybe more

All the usual releases of Firefox also ship with a dark theme these days. Menu > Customize > Themes > Dark.

yes, I meant by default.

Still curious about what's special about the dev edition.

some preconfigured dev-friendly things ? like more verbose logging ...

a separate release channel between nightly and stable ?