Copycat is an analogy-making system written in the late 80s by Douglas Hofstadter and Melanie Mitchell.
Because of my interest in analogy within linguistic morphology I've wanted to experiment with it for a number of years.
Of course I thought about trying to implement it in Python but the other day stumbled across a Python port of a Java port of the Lisp original.
The Python port looked promising but didn't run. So I forked it, fixed a bunch of things the linter complained about and fixed a couple of bugs that were preventing it from working.
My plan is to try to make it more Pythonic and then adapt it to my morphological interests.