Mozilla plans to add a feature to Firefox 57 which enables users to find replacements for extensions that are no longer supported by the browser.
The release of Firefox 57 will make major changes to the browser's add-on system. Legacy add-ons, those that are not WebExtensions, won't be supported anymore as Mozilla plans to focus solely on WebExtensions, a technology used by browsers such as Google Chrome as well.
One effect of the change is that part of Firefox's user base will end up with incompatible add-ons. That's a usability issue obviously as users will end up without functionality provided by these add-ons.
Note: Mozilla marks those add-ons as legacy in Firefox Nightly already. This will come to Firefox Stable as well in time as an indicator that these add-ons will stop working in Firefox 57.
Up until now it was not really clear if and how Mozilla wanted to address the issue. It appears, that the organization has found a way.
Find a replacement
Mozilla plans to add a new unsupported listing to the add-ons manager. You can load the add-ons manager by entering about:addons directly, or with a click on the main Firefox menu button.
All extensions that are no longer compatible when the change hits the browser are moved to that section. This means, that they are not removed right away from Firefox either, but kept for the time being.
40% of Firefox users don't use add-ons according to a 2016 Mozilla study. Those won't notice the change at all.
Tip: Check out Top Firefox add-ons and their WebExtensions status for an overview of what is compatible already, and what is not. Also, find out which Chrome extensions will run in Firefox,
This is good for two reasons: first, because users may notice that the extensions are unsupported. This would not be the case if Mozilla would just delete the add-ons, as users would be left puzzling what happened to them.
Second, because it allows Mozilla to add the recommendation feature to the unsupported extensions listing.
The main idea of the feature is to suggest supported extensions -- read WebExtensions -- as alternatives to unsupported legacy add-ons.
All that users need to do is click on the "find a replacement" link, to get suggestions for comparable add-ons.
The feature is not live yet, but a click on the link will redirect the request to the Mozilla Add-ons website where replacements are then listed on a page.
A couple of things may happen when users click on the button:
- A WebExtensions alternative that replicates all, or most of the add-ons functionality is suggested.
- Suggestions match some functionality only.
- No alternatives are available because a) no one created one, or b) the APIs don't support it anymore.
You probably wonder how many extensions will remain compatible with Firefox. You can find that out here.
The cut that Mozilla makes in Firefox 57 impacts part of Firefox's user base. While there is no study about that, at least none that got published, I'd estimate that it will hurt veteran Firefox users more than it will hurt new users of the browser.
It is clear already that functionality that some legacy add-ons or themes provided won't be supported by WebExtensions, and that these add-ons or themes won't be available anymore, nor will any alternatives to those because of this.
The find a replacement feature will certainly help some users provided that it works correctly, and that is a good thing. (via Sören)
Now You: What's the status of your add-ons currently?