Abstract: A method of queuing messages for communications between computer programs by placing a plurality of messages in a main queue, placing one or more property messages in one or more property queues associated with the main queue and, for each property message, specifying at least one property of a respective message in the main queue and a unique identifier for the respective message. A property name may be specified for a message, or a property value, or some combination of property names and values. An application program interface (API) makes the main queue and the one or more property queues appear as a single priority queue. A message is retrieved from the main queue according to a predefined priority list which includes the at least one property, which can again be a property name, a property value, or some combination of property names and values. The priority list can be dynamically modified.

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.