Surgient. The Virtual Control Server Platform is a virtual environment specially designed for testing complex configurations of virtual machines with Surgient's .

SWsoft. , a unique operating system virtualization solution, eschews hardware emulation in favor of a modified OS kernel that can handle large numbers of Windows and Linux virtual machines.

Virtual Iron. A prepackaged version of the open source Xen hypervisor, competes directly with offerings from VMware and XenSource. Management solutions include LiveMigration, LiveRecovery, and LiveCapacity.

Vizioncore. Targeting VMware environments, Vizioncore is best know for its backup software, but the company also provides VMware migration, replication, and performance management solutions.

VMware. Now an EMC company, VMware maintains its lead in server virtualization with , a full suite of products including ESX Server, VirtualCenter for management, VMotion for migration, and more.