Vimperator that I have been a long time user isn't ready for e10s and the work for porting it to WebExtensions API is going to take a while. Great effort from Vimperator developers over all these years to provide a feature that as a Vim user I have greatly appreciated. I wish I could have helped the project move forward but these days one can only master so many IT skills and Javascript isn't one of mine. With Firefox updates being rolled into Fedora it was imperative that I look for an alternative.
Introducing VimFx, a much lighter add-on that "will be nice to your browser and your habits." [1]. I like that. The not so good news is that VimFx as we know it will only work for the rest of 2017. It's a very active project with a good vibe which gives me hopes that the project will survive the WebExtensions API changes.
[1] | https://github.com/akhodakivskiy/VimFx |