SWsoft, an x86 virtualization software firm that is charging after a market dominated by VMware, is partnering with Microsoft to provide customers 24/7 support.

Under the three-year deal, customers using SWsoft's Virtuozzo software to virtualize servers running Windows will get around-the-clock support.

SWsoft takes a different approach to virtualization than VMware and other competitors such as Microsoft, Virtual Iron and XenSource. It virtualizes above the operating system, meaning that a single instance of Windows or Linux can be partitioned into multiple virtual containers, similar to the approach Sun takes with its Solaris containers. SWsoft's Virtuozzo can support hundreds of virtual environments on a single physical server, the company says.

VMware and the others virtualize below the operating system, slicing servers at the processor level and enabling different operating systems to run side-by-side on a single physical system.

SWsoft's agreement with Microsoft means that if a customer running Virtuozzo for Windows runs into a problem involving the operating system, SWsoft has 24/7 access to Microsoft support to resolve the issue. Customers still come to SWsoft when there is trouble, but SWsoft will have all of Microsoft's expertise and support resources at its disposal, SWsoft says.

"One point of contact, no finger pointing -- better for the end user," an SWsoft spokesman says.