Arc! I love it so much. Vertical tabs and spaces are game changers for me. Also little things like external links opening in a “little arc” window, certain links on the web not opening as full tabs, and having a hotkey to search from anywhere are such nice QoL improvements.
Wish it wasn’t a chromium browser, but the pros it provides in features far outweighs the cons of using chromium (for me).
It was initially called "LiveScript", but since Java applets were really popular at the time of its creation, they went with "JavaScript" instead to get attention.