Despite years of marketing pressure and products that are simpler to use and more widely available, desktop virtualization hasn't taken off to the extent that \n\nvendors and analysts expected even a few years ago. The bring-your-own-device movement among end users, on the other hand, has lit a fire under the market for mobile device virtualization. A survey released last month by telecommunications giant Mitel showed 90 percent of respondents expected virtualization to become more important in their companies, with the priority being first in \n\nmobile phones, second in cloud computing and third in desktop computing. A Frost & Sullivan survey released in this \n\nweek showed that only 5 percent of the 18.3 million tablets sold in 2010 were used in business, but that number could reach 30 percent by 2015. A June, \n\n2010 Frost & Sullivan survey showed 49 percent of respondents expect tablets and smartphones to become the end-user computing platform of choice \n\nwithin a few years. Unfortunately, the number of virtualization products available to connect those devices securely to corporate networks is far thinner than it appears \n\nfrom the marketing and hype surrounding the technology, says Ian Song, research analyst at IDC. "Virtualization on mobile devices requires some pretty low-level coding, especially because there are so many kinds of hardware and firmware, and it \n\nchanges pretty fast," Song says. "Even if you're going to stick with just Android, like VMware plans to do, there are already a lot of different versions, and \n\nanother comes every three or four months."Citrix and VMware PlansCitrix and VMware are both moving fast on products that would make smartphones and tablets good virtualization clients, but the rival firms are taking \n\nvery different approaches. VMware, as part of its Project Horizon mobile computing effort, is basing its mobile client on the Mobile Virtualization Platform \u2014 a Type II \n\nhypervisor designed to run on top of an existing operating system to support one or more additional virtual-smartphone OS\/application-sets on top of that.\nVMware's MVP is also designed to manage multiple profiles, to allow customers to switch from work to personal to other virtual environments \u2014 \n\nwithout losing configuration or applications set up for each.Its Project Horizon, announced in August, creates a cloud-based set of personal configurations, applications and data that users can access from \n\nanywhere, from any device. Though primarily a desktop virtualization product, it can also make BYOD setups far more flexible, by not relying on the phone \n\nto contain all the data and applications, according to VMware.VMware's approach is to work with individual phone manufacturers to build its hypervisor onto their devices, focusing only on Android at this point. VMware and LG Electronics introduced a \n\nvirtualized Android phone in December that is expected to ship sometime early this year, followed by other LG Android devices. A Speed Catch?Type II hypervisors worked well enough on PCs, but far slower than "bare metal" Type I hypervisors because of the additional layer of software on \n\ntop of the operating system, Song says. On phones, which have much less processing power, Type I hypervisors could work much more effectively, but they depend on the ability of the \n\ndeveloper to code them to an incredibly wide variety of hardware, Song says. That's Citrix's strategy, and has been from the beginning, according to Citrix CTO Simon Crosby. The company has been shipping bare-metal \n\nhypervisor clients in its Receiver product line since it shipped an Android version in April, 2010 and plans to continue expanding the line. Citrix has committed enough developers and resources not only to building the hypervisors, but also doing it quickly enough that a new Receiver \n\nversion will be available any time a major new device ships, he says. Even that won't solve the overall problem of having no standard hardware or firmware, however, Song says. "With Android, because it's open and its hardware architecture is open, it's not that difficult to virtualize," he says. "The question is what happens when \n\nyou get to a more closed architecture; I'm not even sure it's legal to virtualize an iPhone at the hardware level."And on software [with a Type II hypervisor], forget about it," Song says. "Apple is not going to let you come in and virtualize it to run another \n\nOS."Follow everything from CIO.com on Twitter @CIOonline.