I see many comments talking about teaching objects with Pharo, we used to use it in the UNQ (a university in Argentina), now we use another Smalltalk flavour, because of the complexity of it. It's called CUIS, developed in Argentina too, the first days we use a framework that uses some similar to prototypes, so the students can start learning objects without the overhead of classes and inheritance. And then we switch…
btw, which was the CUIS prototype framework you used? There should be little reason it couldn't be made to run on Pharo.