Microsoft today announced it will shed functionality from its Windows Server virtualization software in an effort to make good on the company's recent promise of a second-half release.

The retraction of features, divulged on general manager of virtualization strategy Mike Neil's blog, comes on the heels of recently announced delays for the first public beta of the hypervisor, code-named Viridian. According to Neil, the move was made to ensure the company's server virtualization beta will be available concurrently with the RTM (release to manufacturing) iteration of Longhorn, which is currently in public beta.

"Earlier this week we had to come to grips with some universal truths about product development," Neil wrote in his blog. Chief among these truths: "Shipping is a feature, too."

Keeping Viridian on the 2007 road map will also make sure the product's release remains within shouting distance of virtualization rival VMware's proposed summer IPO.

Lost in the shuffle for this iteration of Viridian will be live migration, which enables VMs to be moved from server to server while running; the ability to add resources such as storage, networking, and memory on the fly; and support for more than 16 cores.

The announcement, according to Neil, was made in advance of next week's WinHEC hardware developer conference to ensure "no one is surprised … when we demo all the other innovations in Windows Server virtualization."

The features in question will be incorporated in future releases, Neil wrote.