TL;DR: Firefox used to have a great extension mechanism based on the XUL and XPCOM. This mechanism served us well for a long time. However, it came at an ever-growing cost in terms of maintenance for both Firefox developers and add-on developers. On one side, this growing cost progressively killed any effort to make Firefox secure, fast or to try new things. On the other side, this growing cost progressively killed the community of add-on developers. Eventually, after spending years trying to protect this old add-on mechanism, Mozilla made the hard choice of removing this extension mechanism and replacing this with the less powerful but much more maintainable WebExtensions API. Thanks to this choice, Firefox developers can once again make the necessary changes to improve security, stability or speed. During the past few days, I’ve been chatting with Firefox users, trying to separate fact from rumor regarding the consequences of the August 2020 Mozilla layoffs. One of the topics that came back a few times was the removal of XUL-based add-ons during the move to Firefox Quantum. I was very surprised to see that, years after it happened, some community members still felt hurt by this choice. And then, as someone pointed out on reddit, I realized that we still haven’t taken the time to explain in-depth why we had no choice but to remove XUL-based add-ons. So, if you’re ready for a dive into some of the internals of add-ons and Gecko, I’d like to take this opportunity to try and give you a bit more detail.

TL;DR: Firefox used to have a great extension mechanism based on the XUL and XPCOM. This mechanism served us well for a long time. However, it came at an ever-growing cost in terms of maintenance for both Firefox developers and add-on developers. On one side, this growing cost progressively killed any effort to make Firefox secure, fast or to try new things. On the other side, this growing cost progressively killed the community of add-on developers. Eventually, after spending years trying to protect this old add-on mechanism, Mozilla made the hard choice of removing this extension mechanism and replacing this with the less powerful but much more maintainable WebExtensions API. Thanks to this choice, Firefox developers can once again make the necessary changes to improve security, stability or speed. During the past few days, I’ve been chatting with Firefox users, trying to separate fact from rumor regarding the consequences of the August 2020 Mozilla layoffs. One of the topics that came back a few times was the removal of XUL-based add-ons during the move to Firefox Quantum. I was very surprised to see that, years after it happened, some community members still felt hurt by this choice. And then, as someone pointed out on reddit, I realized that we still haven’t taken the time to explain in-depth why we had no choice but to remove XUL-based add-ons. So, if you’re ready for a dive into some of the internals of add-ons and Gecko, I’d like to take this opportunity to try and give you a bit more detail.

  • kbal@fedia.io
    6·
    3 months ago

    I hope that all the power that add-on developers need can eventually be added to WebExtensions API

    Well it’s nice to see it acknowledged that it’s still lacking even after all these years. It’s not as bad as it was when the old API was abolished, but it’s still missing more many more things than it needs to be.

    Servo seems to be coming along nicely though.

    • tiramichu@lemm.ee
      6·
      3 months ago

      The blogpost was made four years ago, though.

      Quite a fascinating read, nonetheless :)

    • Ephera@lemmy.ml
      1·
      3 months ago

      Not sure what Servo has to do with that. If people want to overhaul Firefox completely, they were always able to fork it…

      • kbal@fedia.io
        4·
        3 months ago

        If you follow the link and scroll down a ways there is a big “the push towards Servo” subheading.

        • Ephera@lemmy.ml
          2·
          3 months ago

          Ah, I really didn’t expect that. Sorry for the dumb comment then. 😅