Even as it started planning Microsoft Azure, its cloud-based platform for designing Web applications and services, Microsoft evolved in its thinking on the nature of the cloud—and drew some inspiration from the architecture behind Bing, its search engine.

So said Bob Muglia, president of Microsoft’s Server and Tools Business division, during a Nov. 17 keynote address at the Microsoft Professional Developers Conference in Los Angeles.

"Over the past year the industry understanding of the cloud has really evolved. One thing that has become very clear is that the cloud is about more than infrastructure: it’s also an application model," Muglia told the audience. "Microsoft has learned about how to build the next-generation application model."

Specifically, Muglia continued, Bing is a prime example of Microsoft’s thinking in terms of cloud application models. 

"Bing is a service that’s always available; it’s highly resilient; it runs on multiple data centers. If we tried to manage this through standard means, it’d be too expensive; what the Bing team did was build an infrastructure on a platform called Autopilot, which can manage the service with a very small amount of human intervention," said Muglia.

In many ways, Autopilot and its automatic data center management are indicative of its thinking in developing the Azure cloud platform.

"Autopilot is a great prototype, but it wasn’t built as a platform that could be generalized," Muglia added. "That’s where Azure has come in—to take these ideas and generalize them in the form of an application platform that can be broadly used."

Microsoft announced during the conference that Windows Azure will be offered as a Community Technology Preview until the end of 2009, with the full switch-on of the cloud platform for enterprises on Jan. 1, 2010. By February of next year, Azure will begin charging for its services.

"At its core, Azure is Windows—Windows Server," Microsoft Chief Software Architect Ray Ozzie said during a keynote speech on Nov. 19. The Windows Azure platform consists of three parts for creating Web applications and services: Windows Azure, an operating system as a service; SQL Azure, a relational database in the cloud; and .NET services, which provide secure connectivity and federated access control for applications.

Combined, Microsoft hopes that the platform will allow it to gain substantial market share against Google, Amazon.com and others making forays into the enterprise-cloud platform environment. Ozzie also introduced a subsystem of Azure, code-named "Dallas," that will function as an open catalog for public and commercial data, as well as a uniform discovery mechanism for that data.

In order to encourage the enterprise’s adoption of Azure, Microsoft announced several initiatives during Day One of the conference, including Windows Server 2008 R2 Hyper-V virtual machine support on Azure, enabling virtualized infrastructure to be moved more rapidly between the cloud and on-premises; Microsoft Pinpoint Marketplace, which will let partners market and sell their applications; and RTM of Windows Identity Foundation, which lets developers provide simplified user access to cloud and on-premises applications.

Muglia announced Windows Server AppFabric, the beta of which will be available for download "shortly." AppFabric is a set of integrated technologies that make it easier for developers to build out and manage middle-tier services built using Windows Workflow Foundation and Windows Communication Foundation. In addition, AppFabric will provide easy-to-use database caching.

A key part of integrating the cloud more fully into enterprise life, Muglia also seemed to suggest, lies in developing models that allow existing applications to be ported into the cloud. Virtualization and infrastructure technology, he added, will come into play with regard to that transfer, and as companies invest more fully in building their clouds.

"What’s important is to begin to evolve these applications," Muglia said, "to take advantage of the attributes that the cloud delivers."