Janet is a nice embeddable Lisp (that is: it belongs to the Lisp family of languages). I've been meaning to play with it, but concluded that the lack of (robust) stdlib would make it hard to use for standalone applications. Was it a problem for you in practice, or is the small stdlib enough for CLI apps?
I mostly stick to using it as a gluing tool for shell scripts for now. So for my purposes it was fine for CLI apps assuming you are gluing together other cli apps. I could have avoided some gluing if Janet had it's own http client. I spent a while trying to dig into some of the packages and to be honest they just aren't there yet. I really wanted to experiment with building a desktop GUI in Janet but I found that it was too much effort to get started. Cljfx (clojure) and racket/gui both work out of the box with minimal effort.
The stdlib is quite enough for basic CLI apps, especially when you use PEGs.
Janet's event loop also makes it very handy for issuing a lot of subprocess calls.
Janet has basic HTTP servers and clients, and there is an effort to shore it up there.