Ladybird is the only browser engine not financially dependent on Google.
It is early days but already becoming usable. I use it to browse sites like OSnews, Hacker News, and LWN.net and it already works pretty well for those.
I was counting WebKit and Blink (Chromium) as cousins, both descendents of KHTML, but maybe they've diverged enough as to not easily be able to borrow from each other any more and it really is three.