Abstract: A version traversal system for objects, such as types, may include a reference to another version of an object with the type definition. The reference may be used to identify an older or newer version of the object which may be in a different assembly and may have a different simple name. The version traversal system may be used to compile applications written for the first version but compiled with assemblies from the second version, as well as serializing and deserializing objects from one version to another. The version traversal system may enable two way communications between applications that use two versions of a set of assemblies. The reference may include a fully qualified name or other identifiers.