Here's an interesting development in the cloud computing wars. Razorfish, the online advertising agency owned by Microsoft, has chosen to use Rackspace's cloud hosting platform. Apparently Razorfish decided not to wait for Microsoft's own cloud computing service, Azure, slated to roll out later this year.

Rackspace will work with Razorfish to "build consumer-facing websites and web applications that can handle large traffic spikes during major promotions and product launches of brands" and support the agency's development of "microsites, community platforms, blogs, and web video for its clients," according to a press release.

"While our clients turn to us for creative and other consumer-facing services, they also turn to us for services on the back end -- services that ensure their sites function at an optimal level even during major spikes in traffic. That’s why we rely on Rackspace," Tobias Klauder, Razorfish director of IT software engineering, said in a statement.

The press release made no mention of Microsoft. Silicon Alley Insider, which first spotted the announcement, described it as Razorfish "loudly endorsing" the platform of a Microsoft rival in the cloud-computing space.

Razorfish, which Microsoft acquired as part of its $6 billion purchase of digital marketing giant aQuantive in 2007, has always been a bit of an odd man out at Microsoft. There's been persistent speculation that Microsoft is looking to unload the agency. In an interview in November, Razorfish CEO Clark Kokich batted down the rumors, but left the door open to a future sale. Razorfish, like other ad agencies, has felt the sting of the recession, and announced several rounds of layoffs in recent months.