I got to meet Brad Cox at college when he came to visit one of my professors (who I worked with after hours). I find it interesting that instead of the objects as tiny computers of Kay he thought of software ICs and then pulled from Smalltalk to implement those concepts in Objective-C, but in the simplest way possible (almost just combining the two side-by-side) as opposed to Stroustrup being more heavily influenced by Similar (especially as he was actually building simulations) and extending C into objects to gain performance that Simula didn’t have.