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. One of the breakthroughs of object-oriented technology is the reusability of code. Objects stored using one programming language can be accessed by other programming languages.