> jank is a general purpose programming language. It’s a dialect of Clojure, which is itself a dialect of Lisp. jank is functional-first, but it supports adhoc mutations and effects. All data structures are persistent and immutable by default and jank, following Clojure’s design, provides mechanisms for safe mutations for easy concurrency.

> Beyond Clojure, jank is brethren to C++ and it can reach into C++ arbitrarily to both access and define new C++ types, functions, and templates, at runtime. This is done by JIT (just in time) compiling C++, using Clang and LLVM. The result is that you can write Clojure code which can access C and C++ libraries trivially.

From https://book.jank-lang.org, for those of us who've never heard of this language