Mozilla and the Firebug team announced today that development of Firebug as a separate Firefox add-on has been discontinued.
Firebug, probably the most popular third-party development add-on for Firefox ever, has been available for Firefox for a very long time.
I mentioned it here in 2008 for instance as one of the top five Firefox add-ons. The Firebug team announced back in 2014 that it would shift development from Firebug the add-on to contributing to Firefox's native development tools instead.
There were good reasons for the change, but the main one was the introduction of Firefox's multi-process architecture. Firebug 2 is not multi-process compatible, and changing code to make it that would have been possible in a recent amount of time with the resources at hand.
Unfortunately, Firebug wasn’t designed with multiprocess in mind, and making it work in this new scenario would have required an extremely difficult and costly rewrite. The Firebug Working Group agreed they didn’t have enough resources to implement such a massive architectural change.
Another reason was that Firefox's built-in Developer Tools got better and better, and that it did not really make much sense to continue work on Firebug if the Developer Tools would offer most of the add-on's functionality already.
Additionally, Firefox’s built-in developer tools have been gaining speed, so it made sense to base the next version of Firebug on these tools instead.
The Firebug Working Group decided therefore that the best course of action was to discontinue development of Firebug 3, and join the Mozilla DevTools team instead to bring Firebug exclusive functionality to the built-in Developer Tools, and to make the Firefox Developer Tools even greater with the added manpower and experience.
The announcement puts development of Firebug 2 to an end. The last version of Firebug is version 2.0.18 released October 7, 2016. This version is still compatible with Firefox, but only if the browser's multi-process architecture is not enabled.
Several features of Firebug found their way into Firefox already:
The DOM panel, the Firebug theme, Server-side log messages, the HTTP inspector (aka XHR Spy), and various popular add-ons like FireQuery, HAR export, and PixelPerfect. Also, over 40 bugs were fixed to close the gap between DevTools and Firebug.
Firebug add-on users may want to check out the "migrating from Firebug" guide over on the Mozilla Developer Network for information on differences between Firebug and the Firefox Developer Tools.
The decision to merge Firebug features into Firefox's Developer Tools, and discontinue Firebug development makes sense on many levels. While it will leave some users behind, the majority will probably have little issues with migrating to the built-in Developer Tools. Mozilla asks Firebug users to report missing features here. (Thanks Sahil)
Now You: What's your take on the decision to discontinue Firebug?