Here is some interesting conversation with open source developer and contributor, Remilia Scarlet who mainly does command line tools, but recently developed an interest on audio programming.
Catch the interview where she shared her experience working with Crystal for her audio projects, Interview with contributor Remilia Scarlet - The Crystal Programming Language
Happy contributing, Crystalists 
!
Really interest story, use lisp as prototype, then rewrite it with Crystal.
AFAIK, the relationship between lisp and Crystal(Ruby) is connect since Ruby is born by the author of ruby programming language @matz, at least, the idea of mixin come from lisp.
Yeah, Lisp was the first to have mixins, via the Flavors object system iirc. I was really glad when I first learned that Crystal had mixins, though it took me a second to realize that they were just modules.
The object system in Crystal is kinda reminiscent of the one in Common Lisp, and I’m really happy about that. It’s definitely not 1:1 (and probably shouldn’t be), though there’s still some things I miss from CLOS, like :before/:after/:around methods. But it’s all minor stuff that I can work around. Moving code from Lisp to Crystal feels a bit more seamless to me than Lisp to Object Pascal, for example, because of their object system similarities.
Has Matz ever commented on Crystal?
Sure! He’s actually one of the original sponsors and gave the keynote at Crystal 1.0 Conference:
