Abstract: User-created object classes may be generated after build-time without requiring modification to and recompiling of the program code. Every class within an object oriented programming environment is assigned a unique class identifier. Every class within a particular hierarchy is assigned a selector identifier. The exemplary class comprises a registration table having a vendor class portion and a user class portion. Classes defined at build-time are registered in the vendor portion of the registration table. User-created object classes are assigned selector identifiers having values of existing classes. These selector identifiers, along with the respective name of the user-created object class, are registered in the user class portion of the registration table. The instantiation of objects from user-created object classes is handled by searching the user class portion of the registration table prior to the vendor class portion.