Building an interoperability API for Sky computing

The federation of Cloud resources can be treated at different levels of abstractions. In this paper we focus on application programming interfaces for building Cloud based applications using services from multiple Cloud providers. A full stack of APIs is proposed to decouple the development of a Cloud-based application from its deployment and execution. A particular attention is paid to the design of the interoperability API aiming to provide programming language interoperability and protocol syntax or semantic enforcements.