1. A method for implementing a multi-user software application on a computer system, the method comprising the steps of: defining a set of apptom classes, each apptom class defining attributes, relationships and responsibilities, the set of apptom classes including a schema, a class, query class, a view class, and an interface behavior class; storing an essential description of the application as data apptoms in a persistent store, each data apptom being a member of one of the set of apptom classes and having relationship and responsibility attributes of the class, the data apptoms being free of program constructs; executing application-independent code to connect to the persistent store using the computer system to access the data apptoms; instantiating the data apptoms in the computer system memory at application runtime, and executing application-independent architectural code to connect the instantiated data apptoms according to relationship data in each data apptom to create an instance of the application, wherein the executing application-independent code uses the data apptoms so that the connected data apptom instances exhibit the behavior of the application.