Exactly. You more commonly hear this when talking about Lisp. Racket is a Lisp and so is Scheme or Common Lisp, and what we mean by that is dialects. In the art

Exactly. You more commonly hear this when talking about Lisp. Racket is a Lisp and so is Scheme or Common Lisp, and what we mean by that is dialects. In the article he mentions J, K and Dyalog as APLs.