Abstract: A mechanism for dynamically resolving polymorphic type dependencies between parallel heterogenous run-time environments is provided. The mechanism comprises a registry of class types for software objects, in which each class type is linked to a hierarchy of bindings rooted at the binding for that class type with descendent bindings in the hierarchy relating to more specific sub-classes. At run-time a pointer to an object is received, and the received static type of that pointer can be looked up in the registry to determine the location in the hierarchy of bindings at which to make an initial query for the most specific sub-class compatible with the dynamic type of the object. Subsequently, beginning at the determined location in the hierarchy of bindings, the most specific sub-class compatible with the dynamic type of the object is determined, and a run-time binding based on the most specific sub-class identified can be selected.