From my understanding this library takes a grammar and generates a run time interpreter for that grammar. Antlr is much more similar as it takes in a grammar, and generates code you can hook into at any part of the grammar parsing.

Racket on the other hand gives you the ability to hook into the new language, convert it to racket syntax and then compile it. As far as I know racket doesn't give you a simple parsing grammar, and you're targeting outputting racket code if you make a language. Though you could always take racket as your AST and target something like C or LLVM if you want it to live outside of racket.

Racket is not necessarily unique in that aspect, it just focuses on making it easier with tooling. Scala, Kotlin, Elixir are examples of some of the most successful languages https://www.youtube.com/watch?v=du6qWa8lWZA