Abstract: A method for detecting the infection of executable computer software programs by memory resident computer software virus programs is provided. The invented method comprises comparing an initial state of an executable program to a final state of the program. If the final state of the program is different than the initial state, then the method generates an alarm signal to inform a user that the program has been modified by a virus and is infected. Particularly, as a program is called into memory, that state of the program is marked as the initial state. When execution of the program is completed, that state of the program is marked as the final state. Alternatively, at the moment when processing of the program commences, that state of the program is marked as the final state of the program. The method compares the final and initial states to determine if the two states match. If the two states are the same, then it is confirmed that the program was not modified and is not infected.

Abstract: An application development system, optimized for authoring multimedia titles, enables its users to create selectively reusable object containers merely by defining links among instantiated objects. Employing a technique known as Hierarchical Encapsulation, the system automatically isolates the external dependencies of the object containers created by its users, thereby facilitating reusability of object containers and the objects they contain in other container environments. Authors create two basic types of objects: Elements, which are the key actors within an application, and Modifiers, which modify an Element's characteristics. The object containers (Elements and Behaviors--i.e., Modifier containers) created by authors spawn hierarchies of objects, including the Structural Hierarchy of Elements within Elements, and the Behavioral Hierarchy, within an Element, of Behaviors (and other Modifiers) within Behaviors.