A software company founded in 2004 by Ian Pratt, Nick Gault and Moshe Bar, who developed the open source Xen virtual machine monitor (the Xen hypervisor). XenSource managed the open source project until 2008, when it was turned over to Xen.org. XenSource's enterprise version was acquired by Citrix and renamed XenServer. See
XenServer and
Xen.