Notice that you use bob.greeting() but bill.greeting (without the parentheses), while Io uses the same syntax in both cases. Whether this is good or bad is most

Notice that you use bob.greeting() but bill.greeting (without the parentheses), while Io uses the same syntax in both cases. Whether this is good or bad is mostly a matter of preference, I think... Of course, this implies that Io would need a separate construct to get the value of a slot (e.g. bob getSlot("greeting")), while in Python you'd just use bob.greeting no matter whether greeting is callable or not.