1. A computer-implemented system for running applications software, the system having a processor, a memory, and a storage medium, the system comprising: a plurality of Models stored in the storage medium, the Models each containing data including references to one or more Objects; and a Run Time Events Manager adapted for loading into memory from the storage medium a selected one of the plurality of Models, reading the data of the selected Model, and when a reference to an Object is read, invoking and executing the Object, wherein the Models are part of a set of Models created according to a registration process wherein a Model is registered only if the Model does not contain a reference to a Method that can invoke another Method, and wherein the Run Time Events Manager can access only Models that have been registered according to the registration process.