[matthewtoast]

Cool! This is a great, clear tutorial.

I strongly recommend this activity to almost any programmer. No matter what, you'll end up with a deeper appreciation for great system design. You realize how almost every design decision boils down to a compromise between convenience and flexibility. For better or worse, you'll also get new respect for the cruel reasoning behind more arcane, but also more flexible APIs. Red pill blue pill kind of thing.

And, just to share: Last year I took a crack at creating a JavaScript-interpreted Lisp and this is the result - https://github.com/matthewtoast/runiq - I haven't added anything since then but I might pick it up again, as it was a helluva lot of fun and also quite mind-expanding.