Is this completely from-scratch, or just a Python interface around existing render and JS engines? In the former case, it's really impressive and exciting.
Edit: Never mind, "qutebrowser uses Qt and QtWebEngine by default (and supports QtWebKit optionally). QtWebEngine is based on Google’s Chromium."
It also shipped as default browser in Sailfish OS.
Huh, qutebrowser did? I doubt that.
There's an alternative in Luakit[1] built with Luajit on Webkit and scriptable with Lua. Also has customizable Vim like key bindings.