Not only that, but I&#x27;m also concerned about the future of addons like Pentadactyl [0] and Vimperator [1] that use XUL.<p>I know the user base of these addons is not anywhere as big as Thunderbird, but I can&#x27;t really imagine using Firefox without Vimperator; and it&#x27;s already started to break in Firefox 45.<p>[0]: <a href="https:&#x2F;&#x2F;github.com&#x2F;5digits&#x2F;dactyl" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;5digits&#x2F;dactyl</a><p>[1]: <a href="https:&#x2F;&#x2F;github.com&#x2F;vimperator&#x2F;vimperator-labs" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;vimperator&#x2F;vimperator-labs</a>