User program gets a handle to an instance of class Container by invoking method New() on class Factory. Class container acts as a handler to the real ARC object which may migrate. It inherits from interface IMyObject through interface IContainer to enforce the abstraction of the user specified ARC object. The container either holds the real object when it's resident, or holds a proxy to it when the object migrates. It delegates the function invocations made by the user to the real instance of class Real which may be available locally or may be migrated to a remote machine. It employs an automatic proxy switching mechanism, which makes migration transparent to a local application program. After the migration, the application program may invoke a method connect() on the container, and subsequently can invoke member functions on it as if the ARC object is available locally. The container reuses a library implementation PContainer through inheritance as shown in Figure 3.