The Azure AppFabric is a set of foundation services that assist in the development, deployment and management of applications. The components of the Windows Azure AppFabric include the Service Bus and Access Control Service:
Service Bus
The Azure Service Bus provides connectivity and secured messaging services between applications running both in the cloud and also on premise. Barriers to communication such as firewalls and network address translation are negotiated automatically by the Service Bus, allowing easy integration of applications and support for hybrid applications. Reliable delivery and scalability are assured allowing developers to focus on the functionality of their applications.
Access Control Service
The Access Control Service allows applications to integrate with identity providers such as Active Directory, Windows Live, Google, Yahoo! and Facebook.
Applications can be separated from the task of authenticating users, allowing this to be changed to other identity providers as required. In addition, the permissions of users inside an application can also be configured using rules, making the application design even simpler.
Microsoft has announced plans to add more services under the Windows Azure AppFabric banner, so expect this list to grow in the not-too distant future. See what new Azure features are coming soon here.
Read more about the Windows Azure AppFabric here.