Streaming the Desktop

Computerworld - Automated software distribution has been a hot topic in desktop management, but the next big thing is on-demand software delivery. While ASD tools help control desktop support costs by making software installations consistent, the on-demand software-delivery technologies go one step further: They can virtualize the local installation and stream the applications -- and even the operating system -- from a central distribution server in real time.

Sanjeev Shetty, director of IT at Time Warner Cable in Greensboro, N.C., is using streaming technology to manage the desktop application environments in the company's 300-seat call center. Shetty says he considered thin clients but couldn't justify the back-end server farm investment required to support an architecture for Microsoft Terminal Services or Citrix Systems Inc.'s Presentation Server (previously MetaFrame).

Instead, he installed Ardence Desktop from Ardence Inc. in Waltham, Mass. It creates and stores complete system images on a server and streams portions of the operating system and applications to desktop users at boot-up. "It didn't require a large investment in server infrastructure and provided immediate ROI," Shetty says.

Application streaming technology takes advantage of the fact that LANs are getting faster -- and that most applications require only a small fraction of the total program code in order to run. The minimum needed can be as little as 10% to 15%, says Dan Kusnetzky, an analyst at IDC.

Once the user is up and running, additional application and operating system components are fetched as needed. After the initial launch of a program, some products allow portions of the applications to reside in a local cache for faster subsequent loads. The result: Applications can be maintained and updated on central servers but run on the end user's local machine. The issue of managing locally installed programs on individual desktops is eliminated.

Image Credit: Isabelle Cardinal

"This concept is new. It's part of the trend toward on-demand computing and utility computing," says Michael Kantrowitz, CEO of Neoware Systems Inc. in King of Prussia, Pa.

Vendors of just-in-time streaming products fall into one of two categories. Companies such as Ardence offer products that stream complete disk images that include the Windows operating system and a predetermined application set. Companies like AppStream Inc. stream only the applications but offer more granular control over application delivery.

Still other vendors, including Softricity Inc. and Stream Theory Inc., take application streaming one step further by creating a self-contained virtual environment in which each streamed application can run. The virtualization layer traps and isolates registry entries, Dynamic Link Libraries (DLL) and other changes the application wants to make to Windows settings. This avoids application conflicts and eliminates the need for administrators to do regression testing and build images for every combination of applications.