The "Similar projects" section [0] contains a concise list of similar browsers, like luakit and surf. Although I've used these two extensively, I always eventually came back to Firefox or Chrome, due to some obscure inconveniences. I hope others are having better luck. I'd sure like to one day see a true variety of popularly used browsers.
[0] https://github.com/qutebrowser/qutebrowser#similar-projects