Firefox WebExtensions: Mozilla aims for Firefox 48

Martin Brinkmann
Dec 22, 2015

Mozilla, maker of the popular Firefox web browser, aims to integrate the first stable release of WebExtensions in Firefox 48.

The organization announced back in August 2015 that it would make fundamental changes to the add-on development process in Firefox. At the core of the change is a focus on WebExtensions, a new API Mozilla is working on to make it easier for developers to create cross-platform extensions, and to reduce the time it takes to review extensions before they are published on Mozilla's official add-on repository.

The announcement did not sit well with some members of the Firefox community. Some developers announced that they would stop developing their add-ons for Firefox, while some community members expressed the desire to move to another browser if Mozilla would implement WebExtensions.

A core reason for the reaction is Mozilla's intention to deprecate Firefox's permissive add-on model and with it XUL and XPCOM which allowed add-ons to be created that are not possible in other browsers due to development limitations.

Critics fear that Firefox add-ons would not be nearly as powerful as before after the switch, that there would be little reason to use Firefox if popular add-ons would not be possible anymore under the new add-on development model, and that the creation of out of the box add-ons would be severely hindered.

Firefox WebExtensions

A recent blog post by Mozilla's Engineering Manager Andy McKay provides insight into the current state of WebExtensions development and milestones.

WebExtensions are in alpha state currently and Mozilla plans to reach the first project major milestone with the release of Firefox 45 in March 2016.

The developers plan to integrate full or partial support for a number of APIs with the release:

With the release of Firefox 45 in March 2016, we’ll have full support for the following APIs: alarms, contextMenus, pageAction and browserAction. Plus a bunch of partially supported APIs: bookmarks, cookies, extension, i18n, notifications, runtime, storage, tabs, webNavigation, webRequest, windows.

Developers may be able to upload webExtensions add-ons to Mozilla's AMO website as early as Firefox 44.

The organization plans to release a WebExtensions beta in Firefox 47 (May 31, 2016), and a first stable release of the API set in Firefox 48 (July, 12, 2016).

Mozilla has created several resources to assist developers in the creation of WebExtensions:

Firefox WebExtensions Resources

  1. Are We WebExtensions Yet reveals the state of development. It lists APIs, bugs and key tracking bugs similar to how Are We e10s Yet highlights the Electrolysis progress.
  2. Core Tracking Bugs: First release, Google Chrome parity, Reddit Enhancement Suite, NoScript.
  3. Chrome incompatibilities.
  4. Mozilla WebExtensions documentation.
  5. WebExtensions examples.

These goals may change depending on the progress that Mozilla makes, tests, and other parameters that may delay the release of WebExtensions.

If things stand as they are, Firefox users may be able to install first WebExtensions add-ons as early as March 2016.

Article Name
Firefox WebExtensions: Mozilla aims for Firefox 48
Mozilla plans to release the first stable versions of Firefox WebExtensions, a new API for add-on development, in Firefox 48.

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  1. LimboSlam said on December 25, 2015 at 12:52 am

    @juju: Where have you been for the last 5 years!?? Open up your eyes man!

  2. reader said on December 23, 2015 at 2:42 pm

    firefox “os” – rip.
    firefox XPCOM/XUl – rip.
    next – firefox “gecko” rip,
    and repeat the scenario of Opera, getting webKit engine.

    1. juju said on December 24, 2015 at 10:11 am

      You have to include Google Chrome in your list. Think of it as a strategy of someone to consolidate power in one hand. Whole thing doesn’t really make much sense except if putting it in a sense of the pride of conquering something. Taste the rainbow.

      1. juju said on December 24, 2015 at 4:18 pm

        to Lestat
        thats totally wrong thinking to use such approach to this dilemma. Google or Mozilla are just two labels that mean nothing. So your reply is null and void.

      2. Lestat said on December 24, 2015 at 1:15 pm

        It is an open secret that Google tries to get rid of every competition. And it is also an open secret that Mozilla’s decisions in the last few years have been influenced from the inside by Google (especially while their “plain and simple” default search engine contract was running)

        Happens if you have no clue at all in protecting your intellectual property or if you allow willingly that a business partner can gain a massive voting right in a companies decision-making process. So it would come as no surprise to see Mozilla’s plans cancelled in the last few seconds and their future engine would suddenly be Blink. Mozilla runs more and more in trouble, Yahoo’s future is uncertain, and a possible buyer could indeed cancel the Mozilla contract, after all Yahoo lost almost all their market share additions again thanks to users switching back to Google or other default search engines as default in Firefox.

        Think about it. Some years ago, no one would have believed that Opera would become a Chrome clone. Also, a while ago almost none would have come to the conclusion that Mozilla’s matchstick and their phones suddenly are standing on the death-row list. And last but not least, almost none would have believed in earlier years that Mozilla is becoming a Chrome UI replica today. The only constant in Mozilla is that there is no constant, and things can happen always and at every time.

        Mozilla really could adopt a similar slogan that Anonymous is using: “We are Mozilla, expect us!”

  3. coakl said on December 23, 2015 at 12:30 am

    If this thing kills off NoScript, I’m leaving Firefox. There wouldn’t be a reason for me to stay.

  4. juju said on December 23, 2015 at 12:03 am

    Mozilla has been cheating and lying through their teeth for a long long time. Think how they fixed this “problem” almost 6 years ago:

    First it wasn’t a security issue, a hole or a leak as they described it. Their approach to fixing it was by changing function to respond to requests with a lie. In other words the question is “Is it a 1 or a 0?”. The response will always be 0 even if it’s a 1.
    What good is the computer that lies to the user that owns it? Even their own DOM and STYLE INSPECTOR who uses this function ends up lying to the end user.

  5. Don Gateley said on December 22, 2015 at 11:12 pm

    I simply won’t update to any release that deprecates what my add-ons rely on. Who would, I wonder, and why?

  6. juju said on December 22, 2015 at 8:19 pm

    Think who will inherit all firefox extensions. It’s PaleMoon. At the same time think of Lavasoft affair.

    I’m not saying it’s intelligence community money laundering. It’s more than that.

  7. Nebulus said on December 22, 2015 at 6:57 pm

    I think that says it all “Much of the specifics of the new API are similar to the Blink extension API. Google has extensive documentation on the API”. (source: )

  8. John said on December 22, 2015 at 6:34 pm

    I hope Classic Theme Restorer and other larger changes to the UI etc will still work. Its simply annoying with the default UI and such of the various browsers.

    1. Joker said on December 22, 2015 at 7:48 pm

      If the addon is touching anything outside the website-area (aka the menus and UI), you can almost be certain it won’t work anymore and won’t be possible to be added as a WebExtensions-addon.

  9. Jason said on December 22, 2015 at 5:54 pm

    Is there a site anywhere that lists which existing third-party addons will work under the WebExtensions framework? I don’t see anything like that at (Maybe it’s there and I just haven’t found it.)

    1. marten said on March 8, 2016 at 7:32 pm

      Web extensions is a totally separate thing. The idea is so you write apps in your browser to turn on your coffeemaker for example or check the temperature of your fridge. Its part of their ‘internet of things’ push. “Extensions” is about moving outside the browser, outside the computer even, like how html5 websockets allow you to connect with IP addresses and local ports directly.

    2. Martin Brinkmann said on December 22, 2015 at 7:02 pm

      Jason, none will work as it is a completely new thing. As Sören mentioned already, the creation of WebExtensions does not impact the availability or compatibility of current add-ons. Those will continue to work, but other Mozilla initiatives such as dropping XUL.. will.

  10. swamper said on December 22, 2015 at 2:34 pm

    Even though I moved to Pale Moon I did it in the knowledge that it too would be riding down a dead end road. In my instance it was simply Australis that made me leave Firefox. In my underastanding as Mr. Hentzschel put it “XUL deperecation will happen”. Web Extensions are coming all over the web. Not just the web the desktop too. The same websites you visit on the web can be run in a browser window on the desktop that can be run solely on the desktop.

    “Web Apps” dop not need internet access to work. They need a browser window. Firefox renders a browser window. There was some confusion here in a previous topic that included discussion about “Web Apps”.

    Web Apps use HTML5 and Javascript to run. They will run served (as in a server) or out of a flat file locally on the desktop in what is basically a server run in it’s own package that allows you local filesystem access. Chrome and Web Kit are already on this and have been a good while. Desktop web apps are up and running well in Electron and web.js among others. That is Chrome and Web Kit respectively. Notice there is no Firefox included here.

    Web Extensions are coming. No amount of heel dragging will stop it. If web apps are getting simple enough for somebody like me to code one then that can’t be anything but good. I’ll likely never build an app to release into the wild. Likely never code on any big project. I just like to make stuff. I like to learn. Web Extensions mean less code in the “Web App”. Makes my head not hurt near as much.

    1. Ron said on December 22, 2015 at 7:45 pm

      >Even though I moved to Pale Moon I did it in the knowledge that it too would be riding down a dead end road.<

      I don't know what you mean by that. . . Pale Moon isn't going anywhere. The naysayers have been preaching Pale Moon's demise for years now, and it's still here and will be for a very long time.

      1. marten said on March 8, 2016 at 7:16 pm

        -The naysayers have been preaching Pale Moon’s demise for years now, and it’s still here and will be for a very long time

        So will old versions of firefox (Palemoon is just firefox 24esr with a few addons built in and lots of self promotion – no new core code). But these older browsers are already having problems with some webpages and it will only get worse over time. I just updated for that reason. A lot of people will probably stick with something like firefox 38esr or whatever the latest version is before the good features are finally axed. That will work for another few years.

        If web extensions are done right they could be awesome, basically allowing anyone who knows javascript to produce diverse apps to do just about anything you want. BUT if they lock them down with mandatory signing or restricted priviledges we’ll be back where we started. Unfortunately given the attitude they have shown so far they probably will.

      2. LimboSlam said on December 25, 2015 at 12:48 am

        @swamper: Then by all means, fork it for us. ;)

      3. swamper said on December 22, 2015 at 9:27 pm

        Pale Moon is nothing but Firefox 24 (if I remember right) with security updates applied. No major updates on the engine since he forked correct? So if Pale Moon is to stay viable somebody has got to do some coding. Coding as in the engine itself. Anybody at Pale Moon got the chops for that? I’ve dabbled in enough code to know old code doesn’t do well mainly because nobody knows what’s really in it. Firefox and any fork will be full of it. Do the folks at PM intend to run an old Firefox engine into the future? When are Web Extensions coming to PM? When the engine running the browser reaches the point it will not load web pages because it doesn’t support the code on the page it will die. Elaborate if I’m not right please. I don’t mind getting my outlook adjusted.

        In other words somebody at PM is going to have to develop a browser engine (or fork a different one) and prove me wrong. I hope they do.

        Moonchild didn’t do a thing there I haven’t done myself in the past. I no longer wish to go through the constant hassle of chasing down what those updates are. I used to compile my own Firefox and Thunderbird. It was fun to me at one time. After a couple years I moved on because it wasn’t near as fun any more. I know because of that experience being a coder to maintain a fork is not necessary.

        I for one hope it does not go anywhere. I don’t like any of these browsers cornering the market on anything and I do favor underdogs. But you can’t outrun the future. You can’t outrun deprecation. Naysayer I am not but I won’t avoid facts. I’ll run PM til it is no longer viable for me to do so. If that day never comes that’s even better.

      4. bren said on December 22, 2015 at 9:17 pm

        “Critics fear that Firefox add-ons would not be nearly as powerful as before”

        The criticism is fact-based; it’s not based on “fear”.
        The WebExtensions framework ABSOLUTELY removes functionality, compared to the current framework which mozilla is (deprecating) abandoning.

        Worse, IMO, “webapps” get to play by a different set of rules, or NO rules, no governance.
        Each runs in its own “container”, immune from inspection/intervention by traditional (e.g. NoScript) extensions.

        Webapps represent an “end run”, a renewed attempt to shove NaCL (native client) -ish apps onto consumer devices across ALL platforms, so that we’re forced to “take it or leave it” (we’re stripped of the ability to intervene, to block ads, to block offensive scripts, to block “gawd knows what” telemetry data being siphoned from our device(s)).

        It’s probable that few users (consooomers) will stand their ground, but I believe the “stand”, the stance, we should collectively take — in order to protect our freedoms (of privacy, of choice) — in the face of a take it or leave it mandate is this:
        Download our app.
        No, thanks.
        You must download our app, or you can’t view our content.
        No. I guess I won’t be viewing your content then. Sucks to be you.

  11. Sören Hentzschel said on December 22, 2015 at 1:23 pm

    > The announcement did not sit well with some members of the Firefox community. Some developers announced that they would stop developing their add-ons for Firefox, while some community members expressed the desire to move to another browser if Mozilla would implement WebExtensions.

    These developers did not understand that WebExtensions and XUL deprecation are two different topics. There is no disadvantage for anyone if Mozilla implements WebExtensions. What really matters for developers is the XUL deprecation but the XUL deprecation would also happen without WebExtensions if Mozilla wants to move to Servo in the future.

    1. mma173 said on December 23, 2015 at 5:53 pm

      Moving to WebExtensions makes sense. Firefox become famous in the beginning because of its compliance to Web standards. However, the long time users who are used to the degree of customization XUL is providing currently wouldn’t like this move. Therefore, IMHO, they should do as what Microsoft did, come up with their Edge — a new drastically different browser that reflects their vision; and keep the Fox as is.

    2. Earl said on December 23, 2015 at 2:16 am

      Right… ’cause all us other devs are just to dumb to “understand”. Or, maybe it’s that Mozilla’s roadmap doesn’t really fit in with our plans?

      Great || Dead + Mozilla = Dead[end]

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