Windows Azure AppFabric gets a commercial availability date

Microsoft officials were vague last year about the company's plans for Windows Azure AppFabric -- a set of services for building composite applications, and complement to Windows AppFabric.

But on March 9, Microsoft's AzureAppFabric  team announced that the final version of Azure AppFabric will be out by April 9.

Microsoft unveiled the AppFabric name and some of its plans for the technology at the Professional Developers Conference in November 2009. At that time, Microsoft officials said AppFabric would exist in two forms: An on-premise Windows Server version and a Microsoft-hosted cloud version. The cloud version, known as Windows Azure AppFabric, is what enables customers to tie together their on-premise and cloud-hosted versions of Microsoft and third-party applications and products.

Even though both sets of services are known as "AppFabric," they include a different set of deliverables. Windows Server AppFabric is a bundle of Microsoft's "Velocity" caching technology, plus its "Dublin" app server. Beta 2 of Windows Server App Fabric went to testers on March 1. Windows Azure AppFabric is the new name for .Net Services (which currently means service bus and access control only).

Microsoft plans to start billing its Windows Azure users for any applications that make use of AppFabric on April 9 at 12:00 a.m. GMT. On March 9, MIcrosoft released a billing preview for the AppFabric technology, providing developers and customers with the same kind of daily use summary they get for Windows Azure and SQL Azure.

Microsoft also made available for download this week Version 1.0 of the Windows Azure AppFabric software development kit, a set of application programming interface libraries and code samples for developers building applications making use of the service bus and access control services.