1. A system comprising: a computer system including at least one computing device, wherein the computer system provides concurrent and dynamic processing of interactions corresponding to the design, use, and modification of models using a declarative application meta-model that provides for self-modification of a collection of the models in response to an interaction, wherein the use of the models includes end user interactions in a run time environment, wherein the computer system binds a model of the collection of models in real-time to dynamically construct an implementation of the model, and wherein, in response to an interaction requesting an ability to make a modification for which a user is authorized, the implementation of the model provides the user a set of models of modification controls.