MCC released the third prototype to shareholder companies in July, 1989. Over five million dollars was spent for the three generations of prototypes. Itasca Systems has added major enhancements and features, improved the performance, and strengthened the code. It now runs on UNIX systems from multiple vendors. Each object has a unique identifier along with a state and behavior.
Attributes represent the state of an object.
A class object collects objects that share the same set of attributes and methods. Subclasses derive from existing classes. The resulting schema, or database definition, is a class hierarchy. Each subclass inherits all the attributes and methods of its superclasses. A subclass may derive from more than one superclass.