[PuercoPop]

Len/Mathematics runs on Cuis Smalltalk. Which has the goal of being small and easy to understand and extend. So it should be to your liking.

I found the difference of the image with the book similar to little exercises to test what I had learned so far.

Also being able to easily introspect the code of what you are interacting with is what makes Smalltalk easily discoverable in my experience.

Disclaimer: I only dabble with Smalltalk every now and then.