Microsoft may be readying one or more versions of its cloud operating system that would be customized for government users, according to my sources.

Currently, Microsoft sells the same set of Windows Azure and Windows Server offerings to government users, alongside all other types of users.

But sources of mine who asked not to be named say there could be one or more versions of Microsoft's Cloud OS platform -- meaning Microsoft's set of public, private and hybrid cloud offerings -- in the works.

The private cloud version of Microsoft's Cloud OS offering may be codenamed "Fairfax," according to my contacts. Fairfax, Virg., is the home of the General Services Administration, and close to other U.S. government agencies. I believe Fairfax is meant for U.S. government users. (I don't know if there might be versions specific to governments in other countries somewhere down the line.)

A Microsoft government cloud OS would be, in some ways, similar to the Office 365 for Government offering which Microsoft rolled out a year ago. Office 365 for Government is a multi-tenant service that stores US government data in a segregated community cloud.

This Cloud OS for government -- if an when it materializes -- wouldn't be based on the Windows Azure OS per se, as Azure only runs in Microsoft's own datacenters. Instead, it would be a customized variant of Windows Server, with physical servers residing on site at government locations, my sources say.

I'd assume Windows Azure Pack will play a key role in any kind of Cloud OS for government offering. Windows Azure Pack includes the persistent virtual machine, service bus, portal, Web sites and a few other components previously available only as part of Windows Azure for use on Windows Server and targeted at hosters.

One of my sources said Microsoft officials have discussed internally the idea of an Azure/cloud OS for the government, but was unsure if this had made it beyond the planning stages at this point.

I asked Microsoft whether Azure for Government and/or something akin to Office 365 for Government was in the works on the operating system side of the house and didn't hear back.

One Microsoft cloud partner said the idea of a cloud OS for government makes sense.

"Contrary to popular belief, 'one cloud to rule them all' will likely not work in the near term," said Sinclair Schuller, CEO of Apprenda Inc, which has developed a private platform as a service (PaaS) offering. "Different industries and sectors have wildly different requirements and regulatory environments. The government is notoriously demanding when it comes to infrastructure and cloud expectations, so having a government specific Azure SKU makes a lot of sense if Microsoft plans on winning that business."