Always has been. Web spec is too hard to implement your own web browser from scratch (nothing can, even Google and Apple, they forked KHTML). So if we not count forks we have only three browsers: Google Chrome, Mozilla Firefox and Apple Safari

@doesnm@doesnm.p.psf.lt I think that, just like a river’s waters (always new, never the same), there is nothing left of KHTML on any browser which was initially based on it. KHTML was a fork of khtmlw itself, if you want to go down that rabbit hole.