[seisvelas]

I use it for quick scripts. I do offensive security. It's a pleasant option when doing things other pentesters would do in Python or Go.

>It seems to have a pretty extensive ecosystem but are the libraries mature?

If you're just doing API calls, file IO, simple networking, then it's more than you'll ever need. If I'm doing something obscure enough to have to worry 'is there a mature library for this in Racket?' I'll just use Python at that point.