Mozilla On Track To Modernize Firefox Add-On Systems And Extension, Leaves Developers Unhappy

The parent company of Firefox, Mozilla is changing the way programmers add extensions to browsers. Mozila will also deprecate XUL and XPCOM simultaneously as these are the foundation for the extension system and the move has irked many Firefox developers.firefox

Desktop manager for Firefox, Kev Needham explained that the move by Mozilla to change Firefox was to support new technologies like Servo and Electrolysis and protect users from adware, spyware and bring down the time consumed to review the add-ons.


Mozilla has laid out a four way plan to achieve its objectives:-

  • Implementing a new API for extension termed as WebExtensions which is largely compatible with model used by Opera and Chrome so that it gets easier to develop extensions for multiple browsers. The new API will be Blink compatible where Blink is the WebKit fork for Google. With this, extensions designed for Opera, Chrome and possibly Microsoft Edge in the future can run Firefox with just a few changes.  This API which is modern and centered around JavaScript has several advantages including by default support to multi process browsers and mitigating risk of malware and add-ons misbehaving.
  • Introduce faster, safer, multi process version of Firefox with Electrolysis which can be used by developers with the add-ons from Firefox.
  • Ensure that customization is provided by third party extensions without diluting security concerns, performance and exposing user to malware. Mozilla will now require all extension signed and validated starting with Firefox 41 due for release in September, 2015.
  • Deprecate XUL and XPCOM based add-ons

Nedham claims further that:-

For the company’s community of add-on developers, the proposed changes will deliver benefits such as greater add-on compatibility on cross-browsers and further require redevelopment of several of the add-ons presently existing.  Mozilla is making substantial investment by expanding its team of engineers, evangelists working on add-ons and render support to the community developing them, and add-on reviewers.

As for the reasons to abandon XPCOM and XUL, Needham stated that though these two constitute the fundamental technology for Firefox, Mozilla has experienced a huge advantage from the ability to write a chunk of the browser using JavaScript. In the process, Firefox will become much more customizable compared to other browsers.  However, the add-on models arising naturally from these technologies are also very permissive. Add-ons also have full access to the internal implementation of Firefox. The absence of modularity also leads to several problems.