1. A computer program storage product comprising instructions operable to cause a data processing apparatus to: provide a first set of modeling language entities and a predefined stereotype construct, wherein: each entity in the first set of modeling language entities has an associated graphical representation, the stereotype construct defines an encapsulation of at least one or more modifications to a second set of modeling language entities selected from the first set of modeling language entities, the stereotype construct has an associated graphical representation, the associated graphical representation of the stereotype construct is configured to display representations of properties of first entities in the second set of modeling language entities that are configurable by an end-user, and the associated graphical representation of the stereotype construct is configured to mask representations of properties of second entities in the second set of modeling language entities that are unchangeable by the end-user; receive input specifying the stereotype construct as a component of an application being developed; and generate the application, wherein the application includes a runtime version of the stereotype construct.