In terms of design, Janet is Clojure-inspired, but very much does its own thing. jank is a Clojure, such that any existing Clojure code you have will work. Largely speaking, only Java intorop needs to be ported, using a reader conditonal.

Beyond that, jank is built on a C++ host and interops with C++. This means you qan use C++ features, such as templates, in your jank code. Janet has a C runtime and any C++ interop will need to be through C's ABI.

Lastly, Janet is usable today while jank is still under heavy development.