Nice that perl got a mention, but it is not especially nuanced. Raku is not a fork of perl, it's a new language. That is why it got a new name. It was intended to be backward compatible, just didn't work out that way. However, Raku's FFI lets Raku code call into perl, and vice versa.
Raku was originally called Perl 6 though. It is a fork, not an unrelated new language.