Microsoft .NET Services SDK

The Microsoft .NET Services were designed to be a set of Microsoft-hosted, highly scalable, developer-oriented services that provide key building blocks required by many cloud-based and cloud-aware applications.
Much like the .NET Framework provides higher-level class libraries that make developers more productive, .NET Services can help developers focus on their application logic rather than building and deploying their own cloud-based infrastructure services.
From an interoperability perspective, the .NET Services are also available to other development technologies through the use of industry-standard protocols such as REST, SOAP, and HTTP.
While more services are in the works, .NET Services currently includes three core components — the Access Control Service, Service Bus, and Workflow service.