[valenterry]

The better the programming language, the less need for a custom language. You can then create the DSL inside of the host language. This requires flexibile syntax to some degree and a fairly advanced typesystem if it should be statically typed - hence not too many languages are a good choice here.

[giraffe_lady]

I don't think there's anything in that comment to indicate that they didn't do it that way. There's a robust discussion about this elsewhere, but people making embedded DSLs is basically routine. They just don't always call them that or have awareness that what they're doing fits that description. But almost all of those will be written in the "host language" of just whatever the containing system happens to be written in.

Some languages are particularly suited for this but other than racket and ruby it seems mostly accidental/incidental to their design.

[valenterry]

Right - but to me it sounded more as if there would be specific new languages being invented, since the author gave Lua and Dhall as examples.