Ask HN: What are the current state-of-the-art Lisp implementations doing?

Thank you for sharing Ferret Lang. I'm excited to try this one out. A year ago I went on a quest for something lisp-like on the Arduino. I came across u-lisp but it seemed limited. I ultimately landed on Forth (not a lisp), which was a great learning experience. I think Ferret was what I was looking for at the time.