Citrix has announced that its server-grade virtualization tool, XenServer, is now available as free software under the GPLv2 license. The Xen hypervisor, which is the foundation for XenServer, has been open source for many years, but XenServer was previously only available under a commercial license.
XenServer 6.2 allows up to 500 virtual machines per physical host and supports both Windows and Linux guest systems. According to Citrix, open sourcing XenServer means that "customers, partners, and developers gain full public visibility into the ongoing development and future of XenServer and can directly engage with us to contribute new XenServer functionality, build deeper integrations, and steer the architectural direction of the platform."

The move marks an attempt by Citrix to regain market share in the open source world that it has lost it since the introduction of the Linux KVM hypervisor. The company hopes for wider adoption of the platform, as well as extra hands for development and testing through the open source community. Citrix also announced the it is launching the XenServer.org website as a community portal.

Citrix will also provide a commercial version of XenServer, which will come with automated installation, security fixes, and software maintenance.