Indeed great and very simple interop with C libs. I have looked and played with CL, Scheme, pico lisp, Clojure and Janet but keep coming back to Newlisp, because 'it just works' (for me), documentation is very good and has a lot of inbuild functions. Regarding the C interop I made some bindings for duckdb, termbox and libui at https://github.com/luxint.