An anonymous reader writes "Compared to an operating-system-level virtualization technology like OpenVZ, Xen — a hypervisor-level virtualization technology that allows multiple operating systems to be run with and without para-virtualization — trades off performance for much better isolation and security. OpenVZ's performance advantage due to running virtual containers in a single operating system kernel can be significant. A performance evaluation study (PDF) done by researchers at the University of Michigan and HP labs provides insight into how big a performance penalty Zen pays and what causes the overheads (primarily L2 cache misses)." From the report: "We compare both technologies with a base system in terms of application performance, resource consumption, scalability, low-level system metrics like cache misses and virtualization-specific metrics like Domain-0 consumption in Xen. Our experiments indicate that the average response time can increase by over 400% in Xen and only a modest 100% in OpenVZ as the number of application instances grows from one to four... A similar trend is observed in CPU consumptions of virtual containers."

moe1975 writes to mention that Bill Hilf has taken a rather aggressive stance with regard to the status of the Free Software movement. With claims like; "The Free Software movement is dead. Linux doesn't exist in 2007. Even Linus has got a job today" it would certainly seem that the next offensive is going to be sponsored by denial. "For the desktop, Hilf sees a new frontier in terms of rich client programming. With more and more services by Amazon, Google, Yahoo and, of course, Microsoft being run as services rather than as software installed locally, it will be up to the desktop to provide richer functionality."