Janet has ~10 web frameworks (half SSG, half dynamic) and many web servers. Joy [0] is the most fully featured stack approach, which Janetdocs [1] runs on. But everything you mention is in the std lib. Here's a certbot in 10 lines only using the extended std lib (called spork): https://codeberg.org/veqq/janetdocs/src/branch/master/ssl-fe... `json/decode` automatically maps json to native data structures. There's a package manager included, which builds all code I've found so far, reproducibly.

As for DS, only arrays, there are maps, arrays and strings, all mutable or immutable. I don't think there's any intention to ever implement functional data structures, but they could "easily" be a library.

- [0] https://github.com/joy-framework/joy - [1] http://janetdocs.org/