Today marks the one-year anniversary of Microsoft's Azure platform being available for public consumption.

To celebrate, Microsoft has announced two additional companies that have made use of the platform for consumer- and business-facing services. One of those is T-Mobile, which used Azure to speed up the development time for its Family Room collaboration tool for mobile phones. The other is Xerox, which used Windows Azure and SQL Azure to help build its cloud-based printing service dubbed Cloud Print.

Microsoft first unveiled its Windows Azure platform a little more than two years ago at PDC 2008. Then chief software architect for Microsoft, Ray Ozzie, positioned the cloud services platform as both a transformation in the company's software as well as in its overall strategy.

The product, which lets developers write programs that live inside Microsoft's data centers, competes with similar offerings from cloud heavyweights like Amazon Web Services, Salesforce, and Google. Microsoft has pushed it to both developers and customers alike, as a way to get the latest version of its server technologies on demand, and in a way that can be scaled up or down depending on the size of their business, or the needs of their applications.

Azure had stayed under Ozzie's leadership until the Azure and Server teams got wrapped into Microsoft's Servers and Tools Business in late 2009. Since then, Microsoft has continued to make improvements and additions to the service, as well as to work toward moving Azure beyond its own data centers, with plans to let businesses run their own private clouds with on-premises Azure appliances.

As far as Azure uptake, or how many companies the technology platform has attracted, Microsoft has opened up on those metrics as the platform has continued to evolve. Shortly after the free trial for businesses ended, Microsoft had said that many of the free-trialers had stayed on as paying customers, but it would not go into specifics. According to The Seattle Times, the official number now stands at 31,000 customers, up from 20,000 last July' that's a 55 percent increase inside of seven months. Prior to that, Microsoft said during its fiscal first-quarter earnings call that it had seen Azure subscriptions grow 40 percent quarter-over-quarter.