Once (partially) a promise of Service Oriented Applications (SOA) now we're talking of... Composable applications:
http://www.computerweekly.com/feature/How-composable-application-can-improve-software-development
Quoting:
"Composable applications is the idea that the functional blocks of an application can be decoupled from the complete applications. These individual component parts can then be more finely tuned to create a new application that is ideologically, if not also functionally, greater than the sum of its parts."
