Amazon today announced the launch of a new Marketplace for desktop apps as a service. Amazon is selling subscriptions to software including Visual Studio and Office, paid on a monthly basis.

The software is run on the virtual desktop infrastructure service that Amazon launched last year, AWS WorkSpaces. These subscriptions start at $25 per month for a virtual Windows 7 desktop (provided by Windows Server 2008 R2). Adding, for example, Office 2013 Professional Plus from the AWS Marketplace is another $15 per month.

To go with the Marketplace, Amazon has released a new tool called WorkSpaces Application Manager (WAM). With WAM, administrators can subscribe to apps for their users, mark certain apps as "required" so they'll be deployed automatically, make other optional apps available for users to provision themselves, and manage updating and auditing. WAM can be used with both applications from the Marketplace and in-house apps.

The applications themselves are virtualized, so are isolated from both the underlying operating system and each other. This in turn streamlines maintenance of those apps; patches and updates don't need to be rolled out to dozens or hundreds of users, instead needing only to update the master image.

Before the Marketplace for desktop apps was available, organizations could still deploy paid apps into WorkSpaces, of course, but these deployments had to be managed and tracked separately. With WAM, the bill for, say, Office just gets added to the monthly AWS bill.

Amazon promotes its VDI as a kind of logical extension of AWS; companies are already moving servers to the Amazon cloud, so why not do the same with their PCs too? The two aren't directly analogous, as users will still need some kind of device on their desks to access VDI desktops, but with VDI the PC replacement lifecycle can be extended even further, and full-fledged PCs can be replaced by dumb terminals (though with these dumb terminals often costing as much or more than PCs, their appeal is limited). There can also be security implications; if laptops are used only to access VDI resources, they needn't contain any sensitive data themselves and, so, can expose companies to much less risk when they're lost or stolen.

The growth of VDI won't necessarily challenge software companies—Microsoft still gets its license money whether Office is being used on a virtual desktop in the cloud or a physical one on premises—but it applies yet more pressure to the already struggling PC vendors.