As expected, Microsoft's Windows Azure cloud computing platform went live this morning after a free month of availability to customers that had previously tested pre-release versions of the service. Windows Azure and its sister service SQL Azure are now available in 21 countries around the world, Microsoft says.

"Starting today our partners will be able to begin selling their solutions to their customers, helping them to reach new markets and increase their revenue," Microsoft General Manager Doug Hauger wrote on the company's corporate blog. "We're hearing great feedback from those who are developing and deploying applications and services across the Windows Azure platform. Since January 2010, thousands of customers have moved from CTP (Community Technology Preview) to production."

Windows Azure provides compute, storage, hosting, and management capabilities, while SQL Azure is Microsoft's cloud-based relational database solution. The services were formally unveiled back in October 2008 at the 2008 Professional Developers Conference (PDC).

Customers who were testing the services were offered various chances to upgrade their free test subscriptions to paid accounts. Those who did not respond simply had their accounts disabled, while any data stored on the services was changed to read-only. Microsoft says it will delete the data associated with any disabled SQL Azure accounts on March 1, while disabled Windows Azure accounts will be deleted April 1.

Additionally, Microsoft has begun beta testing a third Azure service, Windows Azure Drive, which was originally announced as XDrive. Windows Azure Drive provides access to traditional hard drive-based storage and drive letters from cloud-based Azure services. According to Microsoft, this capability will help developers move traditional Windows applications to the cloud more easily