With apologies to Slackware, it is the compile-everything-from-source distro.

Happy user for over 23 years now!

Yes, and unlike NixOS they dont calculate build hashes for the sake of making binary caches. So truly, you have to build from source, even if your recipe is exactly the same as everyone else's. I've never really understood this zealotry around compiling things myself, and boy are there some big (slow to compile) programs out there these days.

They basically started it all, that was what made Gentoo different from everyone else.

I'm pretty sure that is the entire purpose of Gentoo

Yeah, it has binary packages nowadays as well, though.