Looks like qutebrowser in many ways. https://qutebrowser.org/

It also remindes me of Tridactyl[0], which promises to bring vim shortcuts to firefox. I tried it for a while but found that I just enjoy using the mouse more to explore the web, even though I'm mostly a keyboard-only user on the rest of my system.

[0] https://github.com/tridactyl/tridactyl