Citrix: Cloud to carry Xen against VMware

Summary:In part one of our two-part interview, Citrix senior executive Ian Pratt explains how the company is looking to Xen's foothold in cloud computing to mount a challenge to virtualisation leader VMware

Citrix aims to beat VMware at virtualisation. A year ago it bought XenSource, the company created by the founders of the Xen open-source hypervisor, and switched the Citrix business focus to virtualisation.

Citrix made XenServer, the commercial system based on Xen, central to its strategy, and applied a Xen brand to other Citrix products involved in delivering applications to desktops. XenSource staff gained senior positions at Citrix and have been setting the company's future direction.

Ian Pratt, the original project leader of Xen and a founder of XenSource, remains a Fellow of King's College, Cambridge, but is now also vice president for special products at Citrix — and remains chairman of

ZDNet UK spent a day at Citrix's UK headquarters with Pratt and his colleague, Simon Crosby, who has moved from chief technology officer of XenSource to become chief technology officer of Citrix. After lengthy briefings on Citrix products and the future of virtualisation, we sat down with Pratt to understand where Citrix is going and why.

In the first of what will be a two-part interview, Pratt discusses how Citrix hopes to make headway in the virtualisation market.

Q: At the moment there is a lot of publicity for VMware and Microsoft Hyper-V. Is there a danger XenWare will be overlooked — especially as it is difficult to measure market share in virtualisation? Could XenWare become the Liberal Democrats of virtualisation?
A: In the market, there is obviously a big incumbent player, VMware, and Microsoft has a very basic product that covers the low end. And then there is XenServer, which is going head to head with VMware, with an enterprise feature set.

If you look towards the cloud, all the cloud vendors use Xen. It gets used in all the largest deployments, by folks like Amazon and other large providers, because of all the features it offers.

It is very hard to judge what the market share is. With VMware, you just look at VMware's bank account.

But if you are looking at market share for Xen in general, you've got XenServer, Virtual Iron, XenApps and products from other companies. And then there are all the Linux distributions that include Xen, most of which are free, and no-one really has any idea of how many copies are in use.

Even with something like XenServer, because there's a free version, we keep stumbling into customers — particularly people doing software as a service, where it all runs on XenServer Express Edition [the free unsupported version of XenServer].

They haven't paid us any money as yet and they have thousands of servers running it. But we'd much rather they were running our stuff than VMware, because it's an opportunity for us.

With the Cloud Edition we recently announced, there will be lots of people wanting to pay for support and get features added.

If cloud providers are mostly on the free XenServer, is this the whole reason for the Cloud Edition — to turn them into 'real' customers and start getting some money in?
Simon Crosby has this analogy, that Xen is an engine and needs a car built around it. [The point of the analogy is that the Xen hypervisor is open source, with a GPL licence, so users can make additional technology outside that hypervisor and keep it proprietary, building commercial products that work with Xen].

If you are a cloud provider or a big software-as-a-service [SaaS] vendor, you can download the open-source engine and build your own car around it. That's fine if you have the engineering resource to do that, but a lot of this stuff is going to become...

Topics: Tech Industry

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