Firefox and its derivatives. They're the last free bastion preventing a Chromium monopoly on the browser market, which is hugely important - especially these days with Google's push for Mv3.
Shout-out to Vivaldi for forking before mv3 happens. It is chromium based but they are very openly anti-google. It's the OG Chrome devs as far as I understand.
Vivaldi is 95% open source, and I understand that may not be enough for some but I think that's a lot better than most alternatives. It also works great.
The "only 5%" is what distinguishes it from Chromium, so it very much matters. And, that blog post is what I meant when I said they are actively hostile to the FS movement. Basically, they say users do not deserve the freedom to fork because competitors and Bad Guys can use it - very ironic for a product that is itself supposedly "95% based" on a competitor!
The argument that users should not have the freedom to fork because bad guys can use it is very similar to the idea that users should not have privacy or anonymity on the internet because it will be abused by bad guys (the so-called four horsemen of the infopocalypse).