The Azure cloud computing platform is now a billion dollar a year business, Microsoft officials have told Bloomberg.

Azure now joins the ranks of the company's other products that bring in a billion or more dollars a year. Aside from the obvious trio of Windows, Windows Server, and Office, this list includes SQL Server, Exchange, SharePoint, Xbox, Visual Studio, Dynamics, System Center, and online advertising. At current revenue levels, Office 365 is also on track to turn over more than a billion dollars this year.

Amazon Web Services (AWS), by way of comparison, is estimated to have brought in $1.8 billion last year.

Microsoft has been steadily expanding the range of services offered under the Azure umbrella. Initially it was a Platform-as-a-Service offering, providing the ability to deploy applications onto Windows servers with maintenance of the operating system software handled automatically by Microsoft.

This has been expanded with the company releasing Infrastructure-as-a-Service support, allowing the use of custom virtual machines running operating systems of the customer's choosing. (That expansion happened earlier this month.) This new ability should make Azure a lot more competitive with AWS, which had IaaS as a core feature since its inception.

However, the company is still struggling to get its products recognized by cloud users. Bloomberg cited analyst James Staten at Forrester Research who claimed that Microsoft has failed to excite "front-line developers," particularly those at startups. Nonetheless, Staten believes that Redmond could double its Azure revenue over the next year.

The billion dollar revenue includes both direct Azure revenue, and revenue from services Microsoft sells to third parties to run their own Azure-like systems.