No. 4 top underreported story for 2008: All the attention's on server virtualization, overshadowing a bigger potential payoff The story: Desktop virtualization is grabbing the headlines, but a wave of acquisitions and new product releases point to success for application virtualization — and heralds a better way to manage client PCs.If managing large numbers of PC clients is part of your job description, you’ve probably engaged in this arm-wrestling match: IT wants to lock down as many PCs as possible in the interest of security and efficiency, but users want to add applications that require admin rights. Someone is bound to lose. But application virtualization, the leading edge of the virtualization wave, can help create the proverbial win-win.[ Get the full scoop on app and desktop virtualization from InfoWorld’s Randall C. Kennedy. | Find out when server virtualization costs more than it’s worth. ] Moreover, app virtualization makes it possible to run legacy apps that could operate only on an earlier version of Windows, such as NT. Indeed, it may even become the standard way of deploying Windows applications across the enterprise. After Microsoft acquired Softricity, it quickly added the ability to deploy virtual apps via the standard Microsoft Installer (MSI) packages.Say a user wants to run Visio, a bulky application. EMC VMware’s ThinApp, for example, lets you package needed application and operating system files into a container. No device drivers are installed and no registry changes are made because the entire application and its virtual OS are delivered as a single executable file. Compression knocks down the Visio files by about half to 50MB, while ThinApp itself takes just 400K and runs on 2MB of memory.ThinApp is an enhanced version of Thinstall, an application VMware bought (along with the company of the same name) in early 2008. VMware was hardly alone in buying or building application virtualization technologies. Microsoft snapped up Softricity, Symantec took out Altiris, and Citrix built its own app virtualization and streaming solution and made it a feature of XenApp (formerly Presentation Server). Virtualized applications are modular. Although streamed by default, virtualized applications can be configured for offline use, either through caching or by simply copying the application image to the client. And though isolated from the local system –because the application’s registry access and private file set are virtualized — they can still interact with local resources, seamlessly accessing the PC’s storage and print devices, for instance. One limitation: For now, app virtualization is restricted to the Windows platform.The bottom line: With the economy — and IT budgets — in the tank, any incremental advantage you can grab is worth considering. Application virtualization is a good addition to your arsenal of management tools.The top underreported stories of 2008: Full story list | Next: Social networking in business is getting real (really) Software Development