Clarifying Clojure had them in 2007. Scala implementations were inspired by Clojure’s. Both Odersky and Bagwell have given credit to Hickey.

Real World Haskell was published in 2008, followed by Real World OCaml in 2013.

Scala got introduced in 2004, with the first Programming in Scala book, in 2008.

HN had plenty of PureScript and Elm.

FP finally was going to get their spotlight, and then mainstream languages got enough FP features to keep being the go to tooling.

Those are not really the same. Those are N=32 finger trees which have extra benefits (quick slices, for example, quicker insertions).

It’s not a secret that they came from the same zeitgeist but took wildly different approaches, but inspired each other.

I still don’t understand why they’re referred to as persistent vectors rather than immutable vectors, but I digress.

okasaki came first

haskell too had them (IntMap honestly works fine in that use case)