> Maybe I'm foggy on the history. But isn't this like Fork #4 or #5 of some previous AdBlock extension?

IIRC it was written from scratch. It was called uBlock before, then a co-maintainer tried to pull some shit, and the original author had to fork it with a new name (I don’t remember the details, it’s been ages since then).

No selling out yet. The author also explicitly says they don’t accept donations. I don’t think he’s looking for a business model. But if that changes – yeah, the fork button is right there, so I don’t see a big problem here.