It is basically another take on Lisp, and the development approach Lisp Machines had, repackaged in a more friendly syntax.

Lisp was the AI language until the first AI Winter took place, and also took Prolog alongside it.

Wolfram Alpha basically builds on them, to put in a very simplistic way.

It's one of the only M-expression versions of Lisp. All the weird stuff about Wolfram Language suddenly made sense when I saw it through that lens