It’s wide known now that Microsoft is preparing to heavily entering the virtualization market with its upcoming Windows Hypervisor (codename Viridian), expected somewhere between 2008 and 2009 (see the Virtualization Industry Roadmap for a complete picture).
Anyway the already debatable Microsoft strategy about virtualization (see my insight Microsoft, the big absentee of virtualization) could change once again: in a CNET News article Stephen Shankland quoted Mike Neil, Product Unit Manager for Windows Virtualization, saying that his company is working on the lightweight virtualization approach variously known as containers, virtual private servers or virtual environments.
The 3 terms are used in OS partitioning technologies like SWsoft Virtuozzo (read my review of Virtuozzo for Windows 3.5.1 to better understand how the technology works) and Sun Solaris Containers, which share the same operating system base and create multiple, isolated forks of subsequent software installed on top (watch my introductory webcast What is Virtualization? to better understand how OS partitioning is related to virtualization).
This move could provide Microsoft a chance to fill the 2-years gap before shipping the Windows Hypervisor with a new technology surely much more effordable than re-engineering the Windows kernel to accomodate an hypervisor.
It still has to be proven that such a solution would have advantages over traditional virtualization now provided by Virtual Server 2005 R2.