Virtualization is an essential technology for building computational infrastructures tailored to the needs of a research organization. Virtual machines (VMs) enable the specialization of operating systems towards particular tasks, with hardware resources safely and transparently multiplexed by the VM hypervisor. They also allow the decoupling of the physical computational infrastructure management from the management of the user-visible virtual computing facility.

VCT (Virtual Cluster Tool) is a wrapper and a set of modified drivers for OpenNebula which adds support for atomic virtual cluster management with versioning and multiple transport protocols.