A Cloud federator may be used to allow seamless and transparent access by a Cloud Client to Cloud services. Federation may be provided on various terms, including as a subscription based real-time online service to Cloud Clients. The Cloud federator may automatically and transparently effect communication between the Cloud Client and Clouds and desired services of the Clouds, and automatically perform identity federation. A Service Abstraction Layer (SAL) may be implemented to simplify Client communication, and Clouds/Cloud services may elect to support the SAL to facilitate federation of their services.