Why Did Mozilla Remove XUL Add-ons?
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. from https://yoric.github.io/post/why-did-mozilla-remove-xul-addons/