Windows Azure AppFabric

Windows Azure AppFabric provides a comprehensive cloud middleware platform for developing, deploying and managing applications on the Windows Azure Platform. It delivers additional developer productivity adding in higher-level Platform-as-a-Service (PaaS) capabilities on top of the familiar Windows Azure application model.

It also enables bridging your existing applications to the cloud through secure connectivity across network and geographic boundaries, and by providing a consistent development model for both Windows Azure and Windows Server.

Finally, it makes development more productive by providing higher abstraction for building end-to-end applications, and simplifies management and maintenance of the application as it takes advantage of advances in the underlying hardware and software infrastructure.

There are three key components of Windows Azure AppFabric:
Middleware Services

Middleware Services are platform capabilities as services, which raise the level of abstraction and reduce complexity of cloud development.
AppFabric key components

• Service Bus - for secure connectivity and messaging
• Access Control - for identity management and access control
• Caching - for in-memory application cache
• Integration - for common integration capabilities, Business Activity Monitoring and Rules, self-service trading partner community portal and provisioning of business-to-business pipelines
• Composite App - to automate the deployment and management of composite applications as a single logical entity and hosting web services and workflows