Firefox to stop supporting legacy add-ons
 

WebExtensions SDK will be it

The big cheeses of the Mozzarella foundation will ship Firefox 57 as the first version of its browser that will not support legacy Firefox add-ons.

Firefox 57 will support only new add-ons written on top of the newer WebExtensions SDK and add-ons written on the old XUL-based Add-Ons SDK will stop working.

In a blog post last week, Mozilla said it will continue to allow developers to upload and list legacy Firefox add-ons on its add-ons portal (AMO), but they'll only show up for users with older browsers and buried in search results under newer WebExtensions-compatible add-ons.

http://fudzilla.com/news/44779-firef...legacy-add-ons