IT executives exploy virtualized environments to manage applications.Ask IT executives whether they use application virtualization technology and chances are they'll answer, "Well, that depends on your definition."Return to the main virtualization story Vendors have applied the buzzy virtualization label to a number of application-management techniques. Yet in its truest sense, application virtualization means isolating applications in logical containers and enabling them to function independent of the server operating system. Because they hold everything the application needs to operate, the containers act as intermediaries between the applications and operating systems. As discussed in "Virtualization riches," Heartland Financial and Lend Lease use application virtualization technology in this manner, via software from Softricity.Other users apply virtualization-style technologies - but not true application virtualization - to application management tasks. Beverly Enterprises and Hewitt Associates are two examples.A thin-client approachBeverly, which provides healthcare services for the elderly nationwide, relies on Citrix Systems' thin-client technology as the heart of its virtualized application environment (compared with Heartland, which tops off its Citrix thin-client deployment with Softricity's richer application virtualization software). Citrix considers its traditional thin-client model to represent application virtualization because the application's physical and logical layers are separated. In Citrix's virtualization model, application intelligence resides on a centralized server and a virtualized interface on individual local clients, says David Valcik, vice president of technology services at the Fort Smith, Ark., company. Beverly runs clinical and financial applications, Office, PeopleSoft and more applications in this Citrix environment."No data resides on the local devices," adds Don Griffin, Beverly's director of infrastructure R&D. "This allows for rapid deployment and gets rid of the problem of one application affecting any other on the local machine."This model gives Beverly the ability to meet federal compliance mandates such as those specified in the Health Insurance Portability and Accountability Act. Beverly, which operates about 350 nursing homes and other elderly care facilities, keeps its 230 or so Citrix servers, running on HP blades, in a secure location. The applications are wrapped in security software, files for transfer are encrypted using Citrix Independent Computing Architecture technology, and patches are applied much more quickly than previously, Valcik says.At the local facilities, user computers are locked down. For instance, Valcik says, users can't right click or save to the C: drive when they're in the virtual desktop. "We enforce security policies mercilessly," he adds.Besides better compliance management, this application model has benefited Beverly by improving performance and reliability, as well as reducing costs associated with hardware expenditures and allowing IT to focus less on problem fixes and more on business improvements, Valcik says.As one example, Valcik points to the $7 million Beverly has saved in capital expenditure since moving to this model three years ago, from having less hardware to upgrade. It also has saved about $1 million in travel expense, because onsite IT support visits are no longer necessary.The grid wayHewitt, a global human-resources outsourcing and consulting firm, applies grid-computing \u00a0technology from DataSynapse to create a virtual application environment, says Dan Kaberon, director of computer resource management for the Lincolnshire, Ill., company. While net executives tend to think of grid computing as a platform that divvies up compute-intensive tasks, the grid can be used to handle any portion of the application work. With DataSynapse's GridServer software, Hewitt can distribute application services for execution in a virtualized, or grid, computing environment."We try to find the right platform and deployment mode for every application, as there really is no computer that's good for everything," Kaberon says. "There are some applications where the core of the application belongs in one place, but another part of the application might be served better elsewhere. So we cut up the application and put the pieces where they'll run best."For example, Hewitt runs the central record-keeping processes for its benefits business on a mainframe. But the mainframe, which is great for running large-scale transaction and batch-processing operations, is too pricey a platform to run more processor-intensive applications, he says. Instead, Hewitt has created a virtualized application environment in which data from the mainframe gets passed to an Intel-based blade server farm using Linux for processing."We get the advantage of centralization and the economics of distributed computing," Kaberon says.Hewitt has been running a pension administration and calculation application in this mode for more than two years, and a virtualized composed print application for about one year, Kaberon says (see case study). In the case of the composed print application, performance is about 50 times better in the virtualized application environment than in the old setup. This big performance boost came while Hewitt saved about 90%, he adds."For the applications that can exploit this type of model, it's an extraordinary opportunity to very, very quickly gain extreme scalability and economy," Kaberon says. "I've never seen an architecture like it; everything just wants to go fast."