https://github.com/LadybirdBrowser/ladybird

It takes a time to compile the whole project, but a way less than Firefox and Chrome. There is an AUR package for ArchLinux.

IMHO, it is not yet daily-drive usable. Really slow for JS. The window manager is extreme limited (I can not drag tabs outside the window). It can not render steampowered neither youtube (I didn’t test any more websites, just these two). The current setting page is just a window popup with a checkbox for one option. But competition is always good for the users. A web browser is a big project for today standards. Good luck to these developers 💪👍

I tested it the last week from the main git branch, it doesn’t open YouTube homepage, yet.

TLDR; from MIT to GPL.