Portability and automated management of composite applications are major concerns of today’s enterprise IT. These applications typically consist of heterogeneous distributed components combined to provide the application’s functionality. This architectural style challenges the operation and management of the application as a whole and requires new concepts for deployment, configuration, operation, and termination. The upcoming OASIS Topology and Orchestration Specification for Cloud Applications (TOSCA) standard provides new ways to enable portable automated deployment and management of composite applications. TOSCA describes the structure of composite applications as topologies containing their components and their relationships. Plans capture management tasks by orchestrating management operations exposed by the components. This chapter provides an overview on the concepts and usage of TOSCA.