Free to Shop: Citrix Dazzle delivers virtual app store

On the desktop, virtualization is all about control. IT has it. End users, not so much. With the release of Citrix's Dazzle today, IT can give some of that back to users of Citrix's XenDesktop and XenApp virtualized PC environments.

Mick Hollison, vice president of marketing for XenApp, calls Dazzle "A self-service application store for the enterprise." The user interface for the service, based on the iTunes Store model, allows users to subscribe to any application that IT puts on the virtual shelf. "What we're talking about here is a move back toward centralization but with a degree of flexibility and freedom that never existed before," he says.

Under the hood

XenApp, formerly Presentation Server, is Citrix's classic virtualized application delivery service, which is built upon Microsoft's Terminal Services. Windows applications run on the back-end server. The PC or thin client uses special client software, called a Receiver, that uses special protocol to send keystrokes and receive screen updates. XenDesktop uses the same technology to present a complete virtualized Windows PC environment within which XenApp delivers those virtualized applications.

In a XenDesktop environment, not only do the system images run in the data center, where they're easier to manage, but administrators don't have to deal with hundreds, or thousands, of Windows instances. Instead, users work off of a shared master image.

Users do have some control: Citrix adds a personalization layer to its XenDesktop shared virtual hosted desktop environment that allows users to customize their desktop wallpaper, icon placements and other settings.

XenDesktop's virtualized environment is delivered in layers, like building a cake. The provisioning server delivers the user's baseline operating system, then layers on the application set and profile with the user's customizations. The virtualization delivery protocol then presents the entire package to the user.

Dazzle is an adjunct to that: It puts a pretty face on automated provisioning while giving each user a bit more flexibility in terms of the available application sets within their personalized environments.

In a related anouncement, Citrix is introducing a new version of its Receiver for Windows and the Mac (Citrix likens its delivery model to that of a cable TV company. They broadcast and you receive your desktop and application programming on your set top box. Get it?). It is also rolling out a new Receiver for the Blackberry. A version for Android phones such as the Motorola Droid will ship early next year.

Missing link: Offline mode

What's missing? An offline work mode, for one thing. Citrix is working on a product called the XenClient, which will run on PCs that use Intel's "bare metal: hypervisor sometime next year. Like VMware, it will deliver a virtual machine to the desktop for offline operation that gets synchronized when the user reconnects to the office.

Unlike VMware, however, Citrix does not plan to use a virtual machine check in/check out model. The virtual machine will always exist on the end device but be synchronized and updated with the back end host. Hollison promises a tech preview of the technology by year end.

Is XenDesktop right for your organization? That depends on the extent to which these classic objections and limitations to virtualized PC environments apply to your situation.

Related Content:

• Desktop virtualization 2010: Citrix comes knocking The 7 classic objections to PC virtualization.
• VMware gives desktop virtualization a new View Faster performance with the new PCoIP protocol. Lower costs through better back-end scaling. And the promise of offline support.
• Citrix: Building strong virtual desktops six ways From Terminal Services to application streaming to blades, six ways Citrix creates a centrally managed virtual PC.