I wanted to say Hello and Thank You for popularization of Crystal to @BrucePerens!
If someone don’t know who he is (I know him since early 90’es) please Google it or check his website at https://perens.com
I will give you a clue: Open Source and BusyBox.
Here is the post in a blog of Bruce regarding Crystal and Lucky: https://perens.com/2020/06/28/building-a-startup-with-crystal-and-lucky/
Thank You, Bruce!