I'm using this to learn some J, which is an array language descended from APL. It can be remarkably concise--many operations are just a couple characters and apply to an entire array--but alien to people who haven't learned how to read it. Think of Chinese compared to Romance languages.
Right now this is just whatever code I have saved. Some bits of second-round solutions just happened in the REPL and didn't get recorded. There are multiple versions of some things, not hooked up, where I was playing around with different ways to calculate and express things.