1. A computer program product for implementing a pluggable model framework in an application that has a model-view-controller (MVC) architecture, the computer program product being tangibly embodied in an information carrier, the computer program product comprising instructions that cause a computer to: define the pluggable model framework, the pluggable model framework comprising elements that relate to one or more of a development tool for an application, a metamodel that defines development objects associated with the application, a generator for generating code based on the metamodel, and an application run-time, the pluggable model framework comprising an extension point that corresponds to at least one of the elements; and interface a plug-in to the pluggable model framework through the extension point, the plug-in containing data for use with a model used by the application, the data for interfacing to an external system.