When I discovered Clojure, apart from the functional language properties and Java integration it brings with it, I was completely struck by how elegant its codebase is.
From what I remember there is around 60k lines of Clojure itself and pretty much all files were edited like minimum 8 years ago, apart of main file with most of the function utilities.
> I was completely struck by how elegant its codebase is.
Well... I like Clojure but I bet you will reconsider that sentiment if you scroll through https://github.com/clojure/clojure/blob/master/src/jvm/cloju... .
Maybe not "elegant", but quite readable compiler impl. compared to what I have seen. And which (real world) compiler has an "elegant" implementation anyways.