ABaban·Apr 26, 2016
Not only that, but I'm also concerned about the future of addons like Pentadactyl [0] and Vimperator [1] that use XUL.
I know the user base of these addons is not anywhere as big as Thunderbird, but I can't really imagine using Firefox without Vimperator; and it's already started to break in Firefox 45.
[0]: https://github.com/5digits/dactyl
[1]: https://github.com/vimperator/vimperator-labs
In Firefox and Thunderbird: A Fork in the Road