For explicit+dynamic+weak, I think ActionScript 3 fits the bill. The language is dynamically typed by default (an un-annotated variable has the dynamic type, “*

For explicit+dynamic+weak, I think ActionScript 3 fits the bill. The language is dynamically typed by default (an un-annotated variable has the dynamic type, “*”), but you can add type annotations, which are used to guide the implicit dynamic type conversions inherited from AS3’s ECMAScript roots. And the type system has some inherent weakness, such as the fact that the “Function” type isn’t generic: it enforces that a value is a function, but doesn’t enforce anything about its parameter types or return type.