I've checked out Dhall very superficially, but it seems to be aimed at being a strict language to generate YAML and JSON, so IMO it has different goals than Jacl. E.g., an empty list is [] : List Natural in Dhall vs [] in Jacl. Dhall has A LOT of features. It looks more like a programming language than a configuration language. Since its goals are different, Dhall lacks a few features of Jacl like optional commas and underscore support in numbers. etc.