The Viridian hypervisor technology is Microsoft's answer to VMware's dominance in the enterprise server virtualization space with its ESX Server. The beta was originally due out by Q1, but Microsoft recently delayed the release of the Viridian beta until the second half of this year.
Microsoft will integrate Viridian into the OS and design it to scale up to 64 processors. The hypervisor will also allow hardware resources such as networking, processor, memory and disk space to be shared and hot-added.
The hypervisor is also expected to have guest-to-guest clustering for cluster aware applications and offer host-to-host clustering for automatic failover of all virtual machines to a backup host if the primary host fails.
Despite the pushed back beta release date, Viridian is still slated to be available 180 days after Windows Longhorn Server is released to manufacturing in the second half of this year.