Two of the add-ons I use are going to break when Firefox 57 / Thunderbird 57 is released, and it appears that their maintainers have abandoned them: their support web sites no longer work, their support email addresses bounce, and there haven’t been any new releases in a long time.
I am happy to take over maintenance of these add-ons if that is possible, so that I can keep them working for myself and their other users.
Is this possible? If so, how?