This has gotten some attention, especially about a week ago, but I really hope more people will continue to try it and, if interested, support it. It is Firefox, but heavily modified to please a different audience that prefers a slightly different UI than Firefox. It has some of the appeal of Arc, Vivaldi, and the Sidebery extension.
In my view, it is very promising, and all competition in this space is good. Here it is on Github, also.
The UI/UX is so good for a one-person team that I hope it embarrasses Mozilla into actually making serious improvements to their browser for the first time in a decade.
The UI looks mostly like Firefox IMO. Critically, it’s just as slow as Firefox.