iented programming is an enhancement of object-oriented programming that allows decentralized class definition. An application developer who needs new operations associated with classes can implement them him/herself, not by editing existing code for the classes, but as a separate collection of class definitions called a subject. Multiple subjects can be composed to yield a complete suite of applications; class definitions within the subjects will be combined so as to satisfy the needs of all the applications in the suite. A simple example is shown in Figure 1. Neither source code access nor recompilation are required to perform this composition, allowing extension and composition of object-code-only applications. Without eliminating the advantages of encapsulation, this approach eliminates the need for class ownership, and hence for the second, more serious kind of negotiation noted above. An application developer can write all the code needed for the application, irrespective of whic