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Open Source

Wide variety of vendors and individuals opens new opportunities for the hypervisor and provides end-users with numerous places to find support


Over 10 million people use Xen with an ecosystem of more than 2000 commercially certified partners


Architecture enables vendors to create Xen-based products and services for servers, cloud, desktop, embedded, and security-first environments


Hypervisor supports multiple guest operating systems and cloud platforms


Minimal attack surface with key security features like KCONFIG and Virtual Machine Introspection


Architecture enables a degree of scalability, robustness, and security suitable for large, critical, and extremely secure environments


The Xen Project team is a global open source community that develops the Xen Project Hypervisor and its associated subprojects.

Xen (pronounced /’zɛn/) Project has its origins in the ancient Greek term Xenos (ξένος), which can be used to refer to guest-friends whose relationship is constructed under the ritual of xenia (“guest-friendship”), which in term is a wordplay on the idea of guest operating systems as well as a community of developers and users. Learn about the project’s interesting history here.

The community follows a number of principles, including Openness, Transparency, Meritocracy, and Consensus Decision Making.

Find out more about how the community governs itself.

What Differentiates the Xen Project community?

In any Open Source effort, the community makes the difference — and the Xen Project community is a jewel!  Some project communities lose steam after a decade; however, ours is actually becoming more diverse, with increasing organizations stepping in to help build new features.

Innovation is not slowing down but accelerating!

Check out our 2023 weather report to find out more about what the project is doing.

What differentiates the Xen Project software?

There are several virtualization technologies available in the world today. Our Xen Project virtualization and cloud software includes many powerful features that make it an excellent choice for many organizations:

Supports multiple guest operating systems: Linux, Windows, NetBSD, FreeBSD
A virtualization technology that only supports a few guest operating systems essentially locks the organization into those choices for years to come. With our hypervisor, you have the flexibility to use what you need and add other operating system platforms as your needs dictate. You are in control.

Supports multiple Cloud platforms: CloudStack, OpenStack
A virtualization technology that only supports one Cloud technology locks you into that technology. With the world of the Cloud moving so quickly, it could be a mistake to commit to one Cloud platform too soon. Our software keeps your choices open as Cloud solutions continue to improve and mature.

Reliable technology with a solid track record
Conservative estimates show that Xen has an active user base of 10+ million; these are users, not merely hypervisor installations which are an order of magnitude higher. Amazon Web Services alone runs ½ million virtualized Xen Project instances according to a recent study and other cloud providers such as Rackspace and hosting companies use the hypervisor at an extremely large scale. Our software is the basis of successful commercial virtualization products from Citrix, Huawei, Inspur, and Oracle.  It is clear that many major industry players regard our software as a safe virtualization platform for even the largest clouds.

The hypervisor can scale up to 4,095 host CPUs with 16Tb of RAM. Using Para Virtualization (PV), the hypervisor supports a maximum of 512 VCPUs with 512 GB RAM per guest. Using Hardware Virtualization (HVM), it supports a maximum of 128 VCPUs with 1Tb RAM per guest.

Using a multi-layered protection and detection approach is the only way to ensure systems stay safe. To implement truly secure architectures, you need to lock down and control capabilities in critical system components; this is where the hypervisor’s capabilities come into play.

Xen Project sets it apart as the safest and most reliable hypervisor to use for security-first environments because of its architecture, advanced security features (Virtual Machine Inspection, KCONFIG, and Live Patching), and an industry-leading security disclosure process. The Project has an Open Source Security Foundation (OpenSSF) best practices badge, (previously known as the Core Infrastructure Initiative Badge).

Our hypervisor is the most flexible hypervisor on the market, enabling you to tailor your installation to your needs. There are lots of choices and trade-offs that you can make. For example, the hypervisor works on older hardware using paravirtualization, and on newer hardware using HVM or PV on HVM. Users can choose from three tool stacks (XL, XAPI & LIBVIRT), from an ecosystem of software complementing the project and choose the most suitable flavor of Linux and Unix operating system for their needs. Further, the project’s flexible architecture enables vendors to create Xen-based products and services for servers, cloud, embedded/automotive, and desktops in particular for ultra-secure environments.

Our architecture is uniquely modular, enabling a degree of scalability, robustness, and security suitable even for large, critical, and extremely secure environments. The functionality running in our control domain can be run in small modular domains with a minimal kernel and a driver, control logic, or other functionality: we call this approach Domain Disaggregation.

Disaggregated domains are conceptually similar to processes in an operating system. They can be started/ended on demand, without affecting the rest of the system. Disaggregated domains reduce the attack surface and distribute bottlenecks. It enables you to restart an unresponsive device driver without affecting your VMs.

VM Migration
The software supports Virtual Machine Migration. This allows you to react to changing loads on your servers, protecting your workloads.

Open Source
Open Source means that you have influence over the direction of the code. You are not at the mercy of some immovable external organization that may have priorities that do not align with your organization. You can participate and help ensure that your needs are heard in the process. And you never have to worry that some entity has decided to terminate the product for business reasons. An Open Source project will live as long as there are parties interested in advancing the software.

Multi-Vendor Support
The project enjoys support from a number of major software and service vendors. This gives end-users numerous places to find support, as well as numerous service providers to work with. With such a rich commercial ecosystem around the project, there is plenty of interest in keeping the project moving forward to ever greater heights.


We’re proud to have project contributors from a diverse number of notable organizations.

The official Xen Project member organizations include AWS, AMD/XILINX, ARM, XenServer, Vates and Epam.

We regularly measure contributions to the project, which you can see in our Acknowledgement pages.