Peter Norvig has lots of expository code that embodies lots of good design. I find I like to learn the flavor of different kinds of code, but practical codebas

Peter Norvig has lots of expository code that embodies lots of good design. I find I like to learn the flavor of different kinds of code, but practical codebases have so much stuff going on that it's not easy to find the distinctive part. It would be great to see more people do expository versions of familiar software and libraries.