The PitchVMware wants people to be able to access enterprise applications with the same ease and flexibility they enjoy from Facebook and Gmail. That is, on any device, without a thought about where the service originated.\n \n \n \n This is possible with a private cloud computing infrastructure, argues Rick Jackson, VMware\u2019s chief marketing officer. It\u2019s \u201can app store on steroids, integrated with your existing security and authentication services,\u201d he says. Cloud computing takes virtualization\u2014VMware\u2019s specialty\u2014one step further by liberating applications from a specific client device or data center. Apps can be delivered where needed, and served from the place with the lowest overhead.\n \n Many companies are building a cloud software stack. Analysts say VMware has a solid start through its dominance of the server virtualization market and its products that make desktops accessible from anywhere, a concept called virtual desktop infrastructure (VDI).\n The catchVMware is building cloud capabilities with acquisitions, says virtualization analyst Gary Chen of IDC (a sister company to CIO\u2019s publisher). Last year, VMware purchased SpringSource for its cloud-application development tools; Zimbra, which offers cloud-based office productivity tools; Integrien, which provides application-performance analysis tools; and TriCipher, for its authentication software. But the market for private clouds is nascent, and VMware\u2019s success in it isn\u2019t yet assured, says Charles King, president and principal analyst for IT consultancy Pund-IT.\n \n \n \n When it comes to VDI, King says CIOs may feel more comfortable with Citrix, which has a closer relationship with Microsoft and has offered desktop virtualization products for decades. Meanwhile, says Chen, Microsoft is likely to renew its assault on the virtual server market with the next release of its Windows Server software, anticipated in 2011. Although Microsoft remains mum, analysts expect major improvements to the Hyper-V virtualization part of Windows Server. (The most common criticism of Hyper-V is that it offers a limited set of management tools compared to VMware.)\n \n Meanwhile, Red Hat and Citrix, though not big players yet, will continue to nip at VMware\u2019s heels with virtual server products. All these companies are using their virtualization products as foundations for their cloud computing solutions.\n The scoreVMware has demonstrated its ability to stay ahead of the competition\u2014even competition as formidable as Microsoft. When Microsoft jumped into server virtualization two years ago, offering Hyper-V for free, \u201cthe conventional wisdom was that VMware was toast,\u201d says King.\n \n \n \n Instead, King says, VMware has the most complete set of virtualization software for Intel-based servers and is skilled at building partnerships with hardware manufacturers. \u201cCloud computing has to be capable of supporting multiple sources of IT infrastructure,\u201d VMware\u2019s Jackson notes, and unlike competitors such as Oracle or Microsoft, VMware is not tying its software to any specific platform.\n \n The company is also investing aggressively in research, nearly doubling its RaannddD expenditures from 2007 to 2009. \u201cIf and when this vision of the cloud that everyone is talking about comes true, corporate clients working with VMware will be in a very good position to take advantage of these changes\u201d King says.\n The companyVMwareHeadquarters: Palo Alto, Calif.Employees: 7,1002009 Revenue: $2 billionCEO: Paul MaritzWhat They Do: VMware has made its greatest impact in the enterprise with its ESX line of server virtualization software, and it\u2019s expanding its portfolio to include desktop virtualization and cloud computing software. Although VMware is a publicly traded company, storage vendor EMC owns an 81 percent stake.