Virtually Speaking: Presenting -- Presentation Virtualization
If you read this column regularly you most likely know exactly what server virtualization is. You're probably also familiar with operating system virtualization and application virtualization. But are you also familiar with presentation virtualization? Will a semantic proclamation from Microsoft have an impact on the virtualization landscape?
If not, don't panic just yet.
It's a fairly new term in the lexicon It hasn't even made its way into Wikipedia yet.
It seems Microsoft has coined the term, and the good news is it may actually make things clearer in the long term.
First and foremost, presentation virtualization is defined as virtualization technology that does the following:
Isolates processing from the graphics and I/O, making it possible to run an application in one location but have it be controlled in another. It creates virtual sessions, in which the applications executing project their user interfaces remotely. Each session might run only a single application, or it might present its user with a complete desktop offering multiple applications. In either case, several virtual sessions can use the same installed copy of an application.
If this sounds an awful lot like desktop virtualization, you're right. It's also the technology formerly known as thin-client computing, and before that it was called terminal computing.
Desktop virtualization carries another meaning, however, and that's where things have been known to get dicey. Traditionally, vendors have also defined desktop virtualization as technology at the desktop level that is virtualized or partitioned sometimes for test and dev, sometimes to be able to run two operating systems.
In Microsoft's words, desktop virtualization "creates a separate OS environment on the desktop, allowing non-compatible legacy or line of business applications to operate within a more current desktop operating system."
With vendors using the same term interchangeably to describe two completely different technologies, confusion was not uncommon. Now, in Microsoft's world view, desktop virtualization is in Vista country, while presentation virtualization is (or, rather will be) in Windows Server 2008 country.
It makes sense to have two different terms to describe such radically different concepts. As valuable as choice is when selecting a product, it's not so great when categorizing the products. Until now no vendor, not even the mighty VMware, has sought to differentiate.
Say what you will about Microsoft, but there's not much of a downside to clearing up semantic confusion, especially for a technology rapidly becoming mainstream enough for the CFO to acknowledge by name, even if he doesn't entirely understand it. Simplicity for mainstream is the core of Microsoft's success, so it's not surprising that it's setting parameters as it releases product.
Should this terminology stick, it will undoubtedly be a boon for Microsoft, as it removes the bananas from the apple bin as it segments the products. Should the coinage gain street cred and be standardized among the virtualization vendors, it will be a boon for those seeking a virtualization solution as well as the vendors selling to them assuming they can get over the fact that the verbiage is coming from Redmond.
Amy Newman is the managing editor of ServerWatch. She has been following the virtualization space since 2001.