Last year Citrix XenServer went fully open source, at the time I blogged about how the changes were in fact fairly minimal as XenServer was effectively mostly open source but by committing to doing this formally we were hoping to speed up and ease the progress of development by third parties. In fact, I specifically discussed at the time how I hoped this would accelerate the development around XenCenter plugins and of XenCenter alternatives e.g. for Linux. Now several months on, I think we are really starting to see this happen.

Xen Orchestra

This month Xen Orchestra launched its 4th release. It’s a web based, OS-independent alternative to XenCenter for managing XenSerrver deployments. You just open your browser, go to your Xen Orchestra page and that’s it! You can control your whole XenServer infrastructure from there. Xen Orchestra is a creation of Vates, a French company specialized in Open Source solutions. Like Citrix they have chosen to follow a supported open source route with respect to Xen, XenServer and Xen Orchestra (and their other solutions). They don’t sell any software, instead selling support, training and consulting around the software. This 4th release sees the introduction of snapshot management. I think the guys from Vates have done a particularly good job with a clean modern interface design that should work well on mobile devices; you can check out some screenshots and even run through a live demo, here.

xvp – relaunched

For many years, the long established open source alternative to web self-service, xvp has been popular with users. In recent years there has been relatively little new development owing to it being a fairly mature and widely used implementation that satisfied its community’s needs and also due to the community leader Colin Dean moving in a new career direction. Colin has done a wonderful job and whilst the development of new features slowed, Colin and xvp have been very active behind the scenes talking directly to us in XenServer Engineering submitting bugs against XenServer and the SDKs, really hardening the solution. Colin has now handed over the xvp project and product to the community and the new team is currently scoping new features and defining a roadmap. A mature code base like this is an excellent open source project for those looking to move into virtualisation. You can now check out the code and plans on github; and the xvp team are active on our community forums if you want to chat to them on relevant threads, like this one.


XenServer has a long established open API offering language bindings in C, C#, Java, Python and PowerShell. Coupled with open-source code and a world full of bright, ingenious developers – I frequently hear about new products, fully-mature and in-use. A couple of weeks ago, our forum celebrity Tobias Kreidl tipped me off about an open-source high-availability solution, HA-lizard, offering an alternative to XenServer’s own High Availability functionality. XenServer requires three hosts to be used for high-availability, if only two are used the so called “split-brain problem” arises. Those of you familiar with our forums will be well aware of the chat Tobias and I have had on this issue. HA-lizard claim to have developed a solution that solves that issue. Given that the code is all open-source and the solution free you can check it out for yourselves. The company behind the project Pulse Supply developed the code for their own use as a Value Added Distributor (VAD) of products and services for Data Communications, Wide Area Networks and Computer Networking. Third party innovation like this really helps drive innovation around XenServer and makes us consider different ways of looking at and solving problems. I’m really keen to hear what community developers think of the code and solution.


Last year we also saw Lunia Consultants take XenToolBox from prototype to full commercial product by putting their product through Citrix Ready certification. XenToolBox is another web-based XenCenter management alternative also offering backup functionality. It’s free for third parties to join the Citrix Ready partner program and we offer a range of materials and support to help partners make products optimised for interoperability and performance with our products. It’s a step I hope many of the new products we are seeing emerging will take. With XenServer being free, there are already many unsupported users trialling and successfully using these products and by taking that step to join Citrix Ready and certify their products they can widen their potential markets to Citrix supported users. Products like XenToolBox are listed on the Citrix Ready Marketplace where supported Citrix users can check that the products they use have been certified to have been architected safely and will not adversely affect their systems or compromise support agreements.

XenCenter – open source

XenCenter becoming open source under a permissive licence has really improved the material available for third party developers. There’s a lot on our developer zone, including links to the code. Often developers are looking to integrate their own products into XenCenter and the XenCenter plug-in mechanism is perfect for this, there is even a dedicated developer area devoted to help on how to do this.

Writing a XenCenter clone – a student project

A while before XenCenter was open-sourced, I was contacted by a university looking to set up a student product as a practical component of a course on virtualisation. Back then XenCenter wasn’t open sourced. Working with the university we came up with a nice little exercise around how to associate VMs with a host, this is often one of the first things any XenCenter like interface wishes to do. It’s a really nice problem that reveals a lot about VM host affinity and the role of storage offering a lot of insight into hypervisor concepts.

Over the years we’ve come across numerous projects looking to implement functionality overlapping with XenCenter and it’s really worth checking out our developer zone where we’ve written various how to articles on the use of events, how to set up test environments, how to navigate the code examples, VNC examples etc. For community support and chat do also check out the XenServer developer forums.

Maybe one of those students who ended up doing the project is developing the next HA-lizard, Xen Orchestra or XenCenter!