[Mashimo]

At least the linked repository contains 0% Java.

Clojure 79.2%

JavaScript 7.2%

SCSS 6.0%

Rust 4.7%

HTML 1.4%

Shell 0.4%

Other 1.1%

[Antibabelic]

They are referring the Clojure, which is hosted on the JVM.

[victorbjorklund]

In this case it compiles to JS