15. A system that connects a controller layer of an application to a data model and view layers of the application, the system comprising at least one computing device, wherein the at least one computing device includes at least one processor and is configured to provide: an expression engine configured to provide declarative access to the model layer from process logic of the application without having an object in the controller layer interact directly with an object in the model layer, wherein the process logic of the application is defined in a process XML document that includes a plurality of process step elements, wherein each process step element includes at least one operation element, and wherein at least one operation element of at least one process step element of the process XML document is configured to cause a flow of execution to be directed to another process step element; an event manager operative to allow the process logic of the application to register a listener for a trigger that originates from an object within the view layer of the application; and a process component configured to: cause expressions that reference the data model layer to be evaluated by the expression engine relative to the appropriate application instance; register one or more triggers with the event manager; and receive notice from the event manager when an object within the view layer of the application experiences a trigger.
15. A system that connects a controller layer of an application to a data model and view layers of the application, the system comprising at least one computing device, wherein the at least one computing device includes at least one processor and is configured to provide: an expression engine configured to provide declarative access to the model layer from process logic of the application without having an object in the controller layer interact directly with an object in the model layer, wherein the process logic of the application is defined in a process XML document that includes a plurality of process step elements, wherein each process step element includes at least one operation element, and wherein at least one operation element of at least one process step element of the process XML document is configured to cause a flow of execution to be directed to another process step element; an event manager operative to allow the process logic of the application to register a listener for a trigger that originates from an object within the view layer of the application; and a process component configured to: cause expressions that reference the data model layer to be evaluated by the expression engine relative to the appropriate application instance; register one or more triggers with the event manager; and receive notice from the event manager when an object within the view layer of the application experiences a trigger. 18. The system as recited in claim 15 , wherein receiving notice of the trigger includes causing the object within the view layer of the application to identify an application instance that experienced the trigger.