"Who would have imagined the explosion of interest in the cloud?" asked Ray Ozzie, Microsoft chief software architect, at the opening of Microsoft's Professional Developers Conference this week in Los Angeles. Well, Ozzie foresaw it and he listened to developers on how to best position his company.Microsoft has been hard at work in the background developing a cloud strategy that's populated with some concrete products and services. What its done, it seems to me, is carry the notion of platform-as-a-service, the approach that Salesforce.com has excelled at, and moved it a step forward.

Next year Microsoft will flesh out Azure with .Net 4, Visual Studio 2010, Azure AppFabric and still to come developments like the Dallas coordination of Azure applications and legacy applications. To me this is framework as a service, where software can be produced on the platform and the platform supports that software with a wide range of connectivity and services once it's deployed.

Development frameworks already do this for specific languages, such as SpringSource's Java framework, Spring, and the Ruby scripting language's Ruby on Rails or Zend Technologies' Framework for PHP. In the cloud, a multi-faceted tools vendor, like Microsoft, regains an advantage. It can provide ease of use tools to develop the applications and connect them to the environment in which they're to run. It can supplement the application with fast database services through data caching and rapid user response times through an automated content delivery network. This is exactly what Microsoft plans to do with the commercial launch of Azure Feb. 1.

It's little wonder that Amazon Web Services introduced an AWS SDK for .Net for its EC2 cloud just before Microsoft's Azure announcement. If Amazon is to hold the interest of Windows developers, it's got to do more than offer a passive infrastructure that leaves the whole deployment and connection problem to the developer.

Azure is something different from Amazon's infrastructure as a service. Much of the plumbing that an application developer wants his application to work with in the cloud is already there.

Azure will also go further in yielding programmatic control to the developer than the Salesforce platform has done so far, although I think if you like Salesforce style applications, then Force.com, Apex and VisualForce is also an impressive cloud development platform. And there's the rub. You have to like the pattern of the Salesforce environment to succeed there. With framework as a service, a wider set of options is open to the developer and many are going to gravitate toward them.

In the background noise of Microsoft's premier developer event, I hear Ozzie being credited with understanding where Microsoft's strengths lie in a rapidly evolving cloud environment and committing the company to move in the direction that developers wanted it to go.