What does Windows Azure Web Sites bring to Microsoft's cloud?

Windows Azure Web Sites -- the official name for the new Azure hosting framework codenamed "Antares" -- seems to have attracted some interesting backers, even though it's only in test form.

Microsoft took the wraps off Azure Web Sites on June 6. Company officials are expected to explain it more fully on June 7 during a three-hour Webcast, and then next week at the company's TechEd North America show.

But some of Azure's newest partners are already explaining why they're interested in the technology.

Azure Web sites "brings support for more language bindings for different code and services," said AppFog CEO Lucas Carlson. (AppFog, interestingly, is built on top of VMware's Cloud Foundry platform.)

Carlson said by enabling AppFog to run on top of Azure Web Sites, AppFog will allow open-source developers to test drive and/or outright move apps hosted on other clouds from Amazon, HP, RackSpace and Joyent, to Azure with little more than the push of a button. That Azure version of AppFog is in private beta today, with public available coming soon, he said.

"We built a virtual Cloud Foundry API which translates the REST API into Azure’s brand new REST API (that's in Azure Web Sites). We also built technology to sync accounts across our Cloud Foundry and Azure systems. Then we built technology to snapshot and clone applications with their services across entire infrastructures," explains Carlson in a blog post.

"Microsoft has fully realized how important it is to have a platform-as-a-service (PaaS) that can work on PHP, Node" and other open-source platforms and stacks, he said. At the same time, by working with Microsoft, AppFog gets access to the large community of .Net developers, too, he said.

Apprenda, a PaaS vendor in its own right, developed a private PaaS designed to run on-premises. (The idea is like Microsoft's largely missing-in-action Azure Appliance approach, except done in software, rather than delivered as racks of servers.)

Apprenda is now integrating directly with Azure in a way that it can "rope into Azure's resources, all in a single pane of glass," said Apprenda CEO Sinclair Schuller.

"We're removing the public-private distinction," he said. Apprenda Azure is in alpha now with select customers, and is adding more over time. The company expects its solution to be generally available in three months or so.

Forrester Research analyst James Staten blogged bullishly about the changes Microsoft is making to Windows Azure with its coming wave of spring features.

Until now, "you needed a Windows machine to deploy and the target was a Windows server or middleware service. With its June release, Microsoft has finally joined the mainstream by adding a full Infrastructure as a Service (IaaS) offering that lets you deploy just about anything," Staten said.