[syntheweave]

The various flavors of Forth all qualify. They are great examples of how to bootstrap towards a powerful abstraction, starting from a relatively simple context. The 80% of the 80/20 rule here comes from "writing a Forth" being an engaging learning experience.

For anyone who would like to do that, I recommend looking up one of the old standards(FIG-FORTH, FORTH-79, FORTH-83) and implementing the words in them with whatever tools and languages you like. You will hit a point where your early assumptions about the implementation are wrong. Keep going, get it to the point where you are capable of using the metaprogramming words.