For more than a decade, vSphere has set the standard for virtualization platform reliability and robustness. With over 250,000 customers worldwide and the support of over 2500 applications from more than 1400 ISV partners, VMware vSphere is the most trusted platform for any application. 

VMware vSphere also provides a rich set of features and capabilities that competing platforms are unable to match. Customers choose vSphere over competitor solutions because:

• vSphere is The Most Trusted Virtual Infrastructure
• vSphere allows customers to Run Business Critical Application with Confidence
• vSphere allows customers to Respond to Business Faster

Over 250,000 customers have chosen to build their virtual infrastructure on vSphere, trusting their mission critical applications and production environments to the advanced capabilities and features that only vSphere provides. 

  = Available  = Partially Available   = Not Available

	VMware vSphere 5	Microsoft Hyper-V R2 SP1	Citrix XenServer 5.6 FP1
Most Trusted Hypervisor Architecture	True purpose-built, bare-metal hypervisor	Hyper-V part of Windows Server OS	XenServer requires Linux OS
Most Secure Thin Hypervisor	VMware vSphere 144 MB disk footprint	Hyper-V w/ Server Core >3 GB disk footprint	XenServer >1 GB disk footprint
Most Reliable Hypervisor	No Windows/Linux to patch in hypervisor	Unrelated patching due to general-purpose OS	Unrelated patching due to general-purpose OS
Most Efficient Hypervisor	Direct driver model w/ optimized drivers	Indirect driver model; parent OS becomes bottleneck	Indirect driver model; dom0 becomes bottleneck
Most Trusted Scalable Environment	Hot-add vCPU, vRAM Hot-add/extend virtual disk	No hot-add vCPU No hot extend virtual disk	No hot-add vCPU, vRAM No hot add or hot extend virtual disk
Most Trusted Memory Management	Ballooning Transparent page sharingMemory compression	Ballooning only	Very static ballooning, no sharing
Most Trusted Storage Management	Storage APIs supported by 150+ arrays	No storage APIs; relies on 3rd party	StorageLink only supported by 24 storage arrays
Most Trusted by Customers	84% market share (according to analysts)	11% market share (according to analysts	4% market share (according to analysts)
Most Trusted by Analysts	Leader category (according to analysts)	Ranked lower on vision and ability to execute	Ranked lower on vision and ability to execute
Most Trusted by ISV Partners	ISVs support vSphere 1st 1,400 ISV partners 2,500 applications	ISVs prioritize vSphere over Hyper-V	Far fewer ISVs support XenServer