Open source software to build private and public clouds

Note that we never really had a clear name for the XAPI project. The project was initially named after XCP, which is essentially a distribution of the Hypervisor, the XAPI toolstack and various other components. Later, the project also delivered packages into Linux distributions. This has created some confusion in the community! To make this clearer, the project team proposes to name the project after the XAPI toolstack. In other words, the project would be named after the codebase instead of one deliverable that the project produces.

What is the XAPI Project?

The XAPI project is a sub-project (or team) of the Xen Project effort that develops the enterprise ready XAPI toolstack. The hypervisor used with the XAPI toolstack consolidates server workloads, enables savings in power, cooling, and management costs and thus contributing to environmentally sustainable computing, an increased ability to adapt to ever-changing IT environments, an optimized use of existing hardware, and an improved level of IT reliability.

The XAPI team also develops tooling, agents and libraries that are needed to operate a XAPI based system.

What is XAPI?

The Xen Project Management API (XAPI) is:

  • A Xen Project Toolstack that exposes the XAPI interface. When we refer to XAPI as a toolstack, we typically include all dependencies and components that are needed for XAPI to operate (e.g. xenopsd).
  • An interface for remotely configuring and controlling virtualised guests running on a Xen-enabled host. XAPI is the core component of XenServer and XCP.

XAPI adds additional functionality compared to other Xen Project toolstacks, including:

  • Extending the software to cover multiple hosts
  • Enhancing the VM lifecycle, including live snapshots, VM checkpointing, and VM migration
  • Enabling resource pools to include live migration, auto configuration, and disaster recovery
  • Allowing flexible storage and networking including integrated Open vSwitch support and storage XenMotion® live Migration (cross-pool migration, VDI migration)
  • Enabling event tracking, with progress and notification
  • Creating upgrade and patching capabilities
  • Facilitating real-time performance monitoring and alerting
  • Integrations with cloud orchestration stacks
  • Built-in support and templates for Windows and Linux guests


XAPI is licensed under the Lesser GNU General Public License (LGPL2).

Getting XAPI

The XAPI team delivers XAPI as packages into Linux distributions. You can also get XAPI is an out-of-the box installable ISO from XenServer.org (and older version of XAPI from this website through XCP). XAPI can be obtained in the following ways:

  • XAPI is delivered as a source distribution by the XAPI project (see downloads). XAPI source releases are the basis for other XAPI deliverables.
  • XAPI toolstack packages in Linux (or XAPI packages) enable you to build an XenServer-like environment from packages that are distributed via your host operating system's package manager. XAPI packages are only available from supported Linux distributions (currently Debian and Ubuntu). Using XAPI packages provides more flexibility in tailoring your environment to your needs, but comes at the cost of less functionality and a more complex set-up. For more information see XAPI for Debian based distributions and XAPI variants. 
  • In June 2013, XenServer was fully open sourced, which means you can get an source distribution of XAPI from XenServer.org. Note that this removed the need to deliver the XCP as a separate open source distribution on this website (also see FAQ).
  • Before June 2013, XenServer was not fully open sourced and a subset of XenServer called XCP was made available for download from this website. The Xen Project website will continue to host these binaries, but new binaries will not be made available on this site (also see FAQ). This version of XCP installs onto your host from an ISO, providing a complete enterprise-ready out-of-the-box server virtualization and cloud computing platform after install.