Have you written your own esoteric (or not) language? What did it look like?

Question

I've seen a few question regarding stackoverflow users' favorite esoteric (or not) programming languages. There are also questions regarding the implementation of languages. However, I was curious to see if any of you have actually written your own programming language (be it esoteric or not) and I also wanted to know what it looks like.

I enjoy reading about and trying to learn new and inventive languages, so I thought it would be nice to see what the stackoverflow community has to offer. :)

I wrote one for fun a few years ago.

Answer 1

I have written a set of 7 "micro" languages for teaching. Each one is meant to illustrate the key ideas of one of the following full programming languages:

• an untyped version of C
• Scheme
• C
• System F
• ML
• Smalltalk
• Prolog

The languages deliberately look very much one like the other, so that students see only essential differences, never gratuitous ones. I want to do two more, based on Haskell and CLU.

Sam Kamin had the original idea and helped a lot with the design.

Answer 2

The opcodes of my pythonic bacteria, of course

Answer 3

I've been working off and on on DIFL, intended as a declarative text adventure language, but becoming less declarative over time. Its main features are a very loose object system and an action system based on multimethods. (Well, its main features will be, assuming I ever finish it.)