[laksjhdlka]

With λProlog in particular I think it probably finds most of its use in specifying and reasoning about systems/languages/logics, e.g. with Abella. I don't think many people are running it in production as an implementation language.

[OneDeuxTriSeiGo]

Yeah the main use of it is probably in ELPI which is a higher order structural reasoning and AST transform tool for Coq/Rocq.