Please redpill me on APL.
Does it have modern relevance?
J is more used now, I think. You don't have to use the weird symbols. It's a nice language, probably the last stage of autism.
I still write APL programs. It's a good way to concisely express some algorithms, and helps one think of problems differently. It frees me from one at a time thinking; it's a good language that is truly non-von Neumann in principle, at least for the most part. Read Can Programming Be Liberated from the von Neumann Style? by John Backus. It has modern relevance for the programmers who care about their craft, the hackers.
probably the last stage of autism
Far off.
Mixing λ calculus symbols and ∇pl functional symbols in lithp for personal combinators.
(⟵ ∇ ( λ (X) (X X)))
(⟵ ⍢ ( λ () (∇ ∇)))
(⍢ ⍢)Not close either.
Malbolge.
There's aplwiki.com (which covers a lot of array language topics), r/apljk (which has links to various podcasts/videos/articles as well as q&a on array languages).