SWsoft Parallels does Virtuozzo Containers 4.0 thing
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SWsoft Parallels has today launched the finalized version of its anti-hypervisor approach to virtualization, Virtuozzo Containers 4.0. It also appears the company is officially SWsoft no longer. Banish the name from your mind.
A shiny new logo constructed, voilà:

Understated, with a splash of web 2.0 color. A bold departure from horror vacui, yet ultimately grounded in con-...
While big name virtualization houses run multiple operating systems on a single server, Virtuozzo divides a single OS into different "containers." In a nutshell, it virtualizes the OS rather than the hardware.
If you missed our ever-intrepid coverage of the Virtuozzo 4.0 beta, here are the bullet points of enhancements:
- Support for Windows Server 2003 and Red Hat Enterprise Linux clustering services, and backup enhancements.
- Resource controls such as setting limits on bursts of CPU activity.
- Real-time optimization of hardware resources, and an improved Virtuozzo file system to more effectively utilize hard disk resources
Virtuozzo Containers 4.0 is available now at $2,500 per dual CPU. ®
COMMENTS
More than one way to skin a cat
Or rather than pay $2,500 per dual cpu (for a supported product), consider Solaris 10 -- Zones have been around for a couple of years, included at no extra cost, and integrated into the base O/S.
Or free beer&speech via opensolaris.org
Plus ZFS -- throw another filesystem or three at each Zone, resource control via cpu sets and/or fair-share CPU scheduler, mem & network resource mgmt, full visibility from global zone...and RH or Sol8 "brands" as needed.
With O/S virtualisation there's one copy of filesystem buffers/metadata, one copy of all the shared binaries, shared libc text, etc, etc; much more memory efficient -- and harware virtualisation doesn't have to reverse-engineer and second-guess what the guest O/S thinks it's trying to do.
VMware, Xen or LDoms can still be used "under" the O/S for cases where more than one O/S type or version are required.
IMHO containers based virtualisation is underrated
I think that Xen and VMWare still can have IO performance issues (and this is often how things are after the install). Paravirtualised drivers do of course help with this as will further virtualisation features such as IOMMUs. You also have the fact that Xen hard partitions memory.
A containers based approach such as Virutozzo which only has one kernel means that you should get near to or even native IO performance and the memory management can be more flexible giving extra memory to VMs that need it (which of course could be detrimental on very oversubscribed boxes)
Also note that openvz.org hosts the open souce variant of Virtuozzo. The number of VPS providers out there that support openvz or full fat virtuozzo seems much larger than those using Xen at present - so it is well used.
@Kinda surprised...
That would have been another $500k or something to the design house that came up with it. Makes me laugh every time I see those immortal words, "Master Brand" - lol, customers don't think in terms of Master Brands and Sub Brands.

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