Operating system virtualization has continued to get a lot of attention at the end-user level — especially with the recent announcements of Parallels Desktop 3.0 for the Mac and VMWare's Fusion, which also allows Mac users to run Windows applications. But virtualizing operating systems is only one way to do it. Altiris made some news last week with an update to its Software Virtualization Solution (SVS). SVS virtualizes the application, not the OS -- an approach that has real management potential.Altiris has been well-known for its deployment and management products for businesses for a while, and it was acquired recently by Symantec. It was a big deal -- $830 million worth -- that gave Symantec instant credibility in network access control as that company builds is product line for the corporate IT marketplace. And apparently Altiris is prospering.

The SVS product is an interesting one. It lets you create a package or "layer" that contains an application that runs on top of the operating system, but in isolation from it. For end users (and there's a free end-user version of SVS) this primarily means security: an app running in a layer can't interact directly with the operating system to do bad tings. For corporate users it means many different things related to development, support, and management. Wrapping up an application and all the supporting software it needs -- DLLs and so on -- in a layer means that its easier run custom apps because the operating system can stay pristine, and application conflicts can be reduced. (Not that you'd want to do it, but the Altiris folks cite running two versions of Microsoft Office simultaneously as an example.)

The big news was the addition of application streaming to create a new version, SVS Professional, using AppStream's technology. Where SVS had installed layers locally on desktop machines before, now they can be streamed down on demand, with a high degree of control over what happens to them. On office desktops, for example, a set of applications may be represented as icons, and a layer acquired on demand may represent only a temporary instance of the app, and when it's closed it goes back into a managed pool on the server. If the user's computer is a laptop, on the other hand, the user probably wants the layer installed permanently so it can be used offline. There's lots of room for creative customization of services here.

The announcement actually covered two versions of SVS, Versions 2.1 (without application streaming), and SVS Professional (with streaming). Both include support for Windows Vista, which is an inevitable roadmap item for IT departments looking to the future.

If you're interested in playing with app virtualization Altiris SVS is free for personal use, and Version 2.1 is available for download. There are several other utilities and tools available on this neat sandbox Web site for Altiris's user community called Juice.