Hello!
I've been trying out a bunch of languages the past months, and wanted to start some discussion on the usage of other languages than traditional ones (C/++, Perl, Python, etc.).
One of the most interesting ones is Common Lisp. I've written a phlog post on programming in it on the gopher://g.nixers.net, but the main take away is that it is incredibly fun to work with. It's cool because it's not as simple as recompiling your project when you make changes, you can individually compile parts of your program, like a function, and try it out in the REPL afterwards. The downside is that it is very much dpendent on the REPL and it's hard to get a nice binary to send to others. I also find it not very *nix friendly as it isn't good to work with stdin and stdout like most (good) Unix tools.
Another one is Zig. My best description of it is "a modern C". It is basically a huge fork of C, but it's very different. The preprocessor, for example, is gone. One of the most interesting things with Zig is the ability to execute code in compile time. Asserts, if/else checks, anything can be executed at compile time, making it great for debugging. It's completely compatible with the C ABI, so you can use any of your favorite C libraries with it. Therefore, it has great *nix compatibility. Hooray!
Other languages I'm a bit interested in is Julia, with it's multiple dispatch-oriented design and Scheme, being a more simplistic Lisp with the ability to time travel in your programs (?!).

What languages are you most excited about, and how are they to work with in *nix?

Edit: Got an idea for a follow up question: What language do you think future *nix tools will be written in? Will they be written in C, or something more modern like Go?