Citrix joins The Linux Foundation, looking for a Xen-powered kernel?

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In 2007, when Citrix, one of Microsoft’s strongest allies, acquired XenSource, a startup whose success depends on an open source product (the Xen hypervisor), nobody really believed the move would benefit the community in any way.

The major concerns were that, over time, Citrix would abandon the development of Xen to focus on a proprietary hypervisor, that Citrix could try to influence the Xen development to provide an indirect advantage to Microsoft and/or that Citrix could use its influence on the Xen project to damage all the competitors that were relying on it (at that time Virtual Iron, Novell, Red Hat, Sun and Oracle).

After the XenSource acquisition, some major vendors (Red Hat and IBM for example) and individual contributors lost interest in the Xen project and started to focus on KVM (IBM effort, Red Hat effort). Possibly because of this relationship between Citrix and Microsoft, possibly because Citrix has never been an open source champion.
Of course VMware did all its best to facilitate the exodus from the Xen project. is unable to exactly track or measure the Citrix contributions to the Xen project since the XenSource acquisition, which made progresses in the last two years and has an impressive roadmap.
People more informed on this aspect are welcome to comment to the post with details.

For sure Citrix approached the open source world from different angles: it invested in the networking vendor Vyatta, which competes against Cisco an open source software router; it’s behind the development of the first open source virtual switch for virtual infrastructures, the Open Virtual Switch, and now it’s supporting the creation of an open source cloud computing platform, the Xen Cloud Platform (XCP).

Whatever the company has done so far, it was not enough to convince Linus Torvalds and the other Linux maintainers to include Xen in the kernel, side by side with KVM.
It seems like just a technical issue, but maybe it’s more than that.

The Citrix new move to the open source world is joining the Linux Foundation.

The official reason behind this move is to ensure that the Linux operating system works the best inside its XCP cloud and in the upcoming client hypervisor XenClient:

“The Linux Foundation provides a neutral forum for collaborative work on requirements for Linux and complementary projects such as the Xen Project, Xen Client hypervisor Initiative (XCI) and Xen Cloud Platform (XCP) initiative,” said Ian Pratt, founder and chair of and vice president of Advanced Products at Citrix Systems. “Citrix has joined the Linux Foundation both in its role as leader of the Xen Project and because it ships commercial products based on Xen.”

In addition to developing the Xen hypervisor, the Xen community is working on the development of complete client hypervisor and cloud virtualization platform products, which incorporate Linux as an embedded, secure, optimized run time for the Virtual Machine Monitor. The Xen community also develops open source technology to permit Linux to run with optimal performance on other hypervisors, such as Microsoft Hyper-V and VMware ESX Server.

Anyway, it’s probably safe to speculate that more than anything else, Citrix wants to see Xen shipped out-of-the-box with every Linux distribution in the market. And becoming a Linux Foundation member may be the first step to achieve the task.