NOT DISTRIBUTE Open , reusable object models

Code reuse between different object model implementations is rare. Most object models cannot easily be shared because they are implemented at a lower level of abstraction than that of the language in which they are designed to operate, rendering their semantics opaque and unavailable for modification by end users. We show that three object types and four methods are sufficient to bootstrap an object model whose semantics are described entirely in terms of those same objects and messages. The result is a simple but powerful object model that can be implemented easily and efficiently, in which all semantics are exposed and malleable, facilitating extensibility, interoperability and implementation reuse.