Embodiments are directed to providing an application model for implementing composite applications and to providing a declarative programming model and distributed runtime for creating and executing composite applications. In an embodiment, a computer system instantiates an application model. The application model allows users to compose composite applications. The composite applications are configured to run on both distributed computing systems and local computing systems. The computer system receives user input at the instantiated application model. The user input indicates which composite application components are to be used in conjunction with each other to form the composite application. The computer system also provides the composite application on a distributed computing system and/or a local computing system.