Corrected version

Microsoft's cloud computing platform Azure is a year old today, and Microsoft says it now has 31,000 customers. The new number is a 55 percent increase from the 20,000 customers Microsoft said Azure had in July.

Observers are watching Azure closely as a sign of how fast companies are moving to cloud computing. Microsoft is competing with IBM, Amazon.com, Salesforce.com, Google and others to get businesses to build applications and store data in remote data centers.

Microsoft highlighted a few different customers: travel website Travelocity has moved its analytics tracking to Azure, Xerox has built a cloud printing service on Azure, and T-Mobile USA built its Family Room application on Windows Phone 7 on Azure.

Last year, the companies that jumped into Azure were start-ups that wanted to outsource server infrastructure and niche companies with large computational needs. It appears that larger companies are now experimenting with building new projects in the cloud.

"One of the things we’re seeing is cloud computing is moving away from a buzz word to chest beating to something with real business benefits," said Amy Barzdukas, general manager in the Server and Tools business at Microsoft.

Barzdukas also said the discussion is now less about efficiency and reduced costs result from having a cloud provider take over server infrastructure and more about using cloud computing to create new applications.

"Remember when we had that Internet [first] coming through? I was working in the marketing and we were really, really happy because we could post the catalog on the Web instead of mailing it," Barzdukas said. "It was only once we had it up that we realized you could do e-commerce and things you could never think about. That’s what we’re seeing with the cloud."

T-Mobile's Family Room application is a social network for family members. It has a chalkboard for members to share messages with each other, a shared calendar and a shared photo space. Matchbox Mobile built the app for T-Mobile.

"We wanted to bring smaller groups of people together, in contrast with some of the social sites out there, which are basically trying to drink from a firehose and aren’t as private as a lot of people are comfortable with," said Josh Lipe, product manager for T-Mobile. The application is preloaded on every Windows Phone 7 sold through T-Mobile.

Lipe said the company went with Azure because it was faster to develop on and it had more features for development. "

The main one was time frame and development cost. "We looked at Azure as being able to quickly integrate with development we were performing on the application" with Visual Studio, Lipe said. "The development kits for the other cloud services weren’t as well baked with nearly the options for development."

Also, Lipe liked that Microsoft guaranteed the platform wouldn't change for T-Mobile for 12 months, so he knew the application would not need a major update for a year. It took two months to build the application, Lipe said. "There’s no doubt in my mind that this was fastest implementation we would have put together," he said.

Lipe said Windows Phone 7 is "doing well" for T-Mobile. "We’re continuing to look at options with Microsoft how to move the platform forward. The customers are very satisfied with the experience. We’ve done well with the devices that we sold."

Information in this blog item, originally published Feb. 1, 2011, was corrected Feb.4, 2011. Based on information provided by Microsoft, a previous version of this item said Travelocity had moved its analytics tracking to Azure. It should have noted that "certain" analytics tracking had been moved.