Microsoft put some meat on the bones of its cloud computing initiative Tuesday, announcing a long-awaited pricing structure and a commercial release date coming in November.

The Redmond, Wash., software company also sweetened the meal a bit for partners, announcing at the Worldwide Partner Conference that partners can start building on the Azure platform for free from now until the official November launch date, when pricing then will be applied. The platform can be accessed at www.windowsazure.com.

Why the four-month free pass? Bob Muglia, president of Microsoft’s Server & Tools business, said the company wants to build momentum behind the platform prior to taking it to general release.

“We are going free now because we really want to build the ecosystem and get people going with development,” Muglia told partners during his keynote address. “Now is really the time to start building Azure apps.”

Muglia stressed that developers who have built applications on .NET, C# or any of the major Microsoft development tools can use those existing skills to write applications for the Azure cloud platform.

The company announced three ways to access and pay for Azure:

• Pay-as-you-go consumption
• Subscription-based consumption
• Integrated into volume licensing

The pay-as-you-go model will sport the following consumption-based pricing metrics for users:

Windows Azure

Computing: $0.12 per hour
Storage: $0.15 per gigabyte stored
Storage transaction: $0.10 per 10K
Bandwidth: $0.10 in/$0.15 out per gigabyte

SQL Azure

Web Edition Database, includes up to 1GB relational database for $9.99
Business Edition Database, includes up to 10GB relational database for $99.99
Bandwidth for both: $0.10 in/$0.15 out per gigabyte

.NET Services

Messages: $0.15 per 100K message operations, including service bus messages and access control tokens
Bandwidth: $0.10 in/$0.15 out

Service-level agreements

Compute Connectivity: 99.95 percent guarantee
Storage: 99.9 percent guarantee
Automated Service Management: automatically reinstantiates an application

The subscription-based consumption model is intended for Azure users who want predictability and fixed pricing, Muglia said. Meanwhile, Microsoft integrated the Azure licensing into its volume licensing program so that customers on enterprise agreements can gain access to the cloud platform as well.

Members of the Microsoft Partner Network (formerly Microsoft Partner Program) will be given a 5 percent upfront promotional discount on Azure Windows, SQL and .NET services. Microsoft bills the partner directly, but partners can then set their own prices to their end customers, Muglia explained.

Partners have been clamoring for concrete information on how pricing for the cloud services would work so they can begin realigning their own business models. As one partner put it last week in advance of WPC, “Without a pricing model for Azure it is simply technically cool … and that is just not good enough.”