Anyone else have any experience messing with these? I kind of inadvertently fell into them. I had some work I had to do in Scheme, and the online compiler I ended up using had support for a few esoteric languages (Emoticon, unlamda, LOLCODE, and Brainfuck), and seeing them listen re-piqued my interest.

For anyone who isn't familiar with them, esoteric languages generally seemed designed to just be a pain to use for one reason or another. Some just use unusual names for things (like LOLCODE), but most operate in entirely different ways than most of the languages you'd be accustomed to.

Take Brainfuck (my current favorite), for instance. It's only got 8 possible commands, and operates basically like a Turing machine. This makes doing anything take quite a while, but it's an interesting challenge to try and implement things like multiplication and division without resorting to just looking up the algorithms. A Brainfuck derivative called Braincopter also works well for steganography by essentially supporting encoding Brainfuck programs as images.

I've got a whole list of these I want to eventually spend some time messing around with, but thusfar I've only used brainfuck and briefly dabbled in whitespace (which looks exactly how it sounds).