VMworld 2009 is over and the battle lines are already drawn between Citrix Xen, Vmware and Redhat. Xen is the leader in the public cloud service provider side and VMware holds near monopoly hold on the enterprise infrastructure side. Before we see full scale cloud adoption on the enterprise side, it is important that these technologies interoperate with one another.

This week saw major announcements from all three virtualization players that could eventually lead to an open federated cloud ecosystem. But it is just a start and these efforts should go well beyond the soundbites of the occasion. It is a long road ahead but it is important that the process is kickstarted sooner than later. Let us recap the events that unfolded this week and try to understand it from the framework of open federated cloud ecosystem.

Anticipating an announcement by VMware, Xen.org, the competing virtualization hypervisor backed by Citrix systems, announced their Xen Cloud Platform (XCP), an open source cloud computing platform built on top of Xen hypervisor. The Xen Cloud Platform will accelerate the use of cloud infrastructure for enterprise customers by providing open source virtual infrastructure technology that makes it easy for service providers to deliver secure, customizable, multi-tenant cloud services that work seamlessly with the virtualized application workloads customers are already running in their internal datacenters and private clouds, without locking them into any particular vendor. The goal of XCP is to

• create a cloud computing platform with storage, servers and networks virtualized. The virtualized storage and servers are architected to be widely separated without disrupting application performance. The rich virtual networking capabilities adds sophisticated network service offerings, including per-tenant network management, intrusion detection, firewalling, routing, and load balancing
  
• run across many different virtualization platforms including Microsoft and VMware. Using different standards such as Distributed Management Task Force (DMTF) Open Virtualization Format (OVF), virtual appliances will be packaged in a hypervisor-independent format for easy transport between internal and external clouds with no proprietary vendor lock-in
• port applications running on enterprise datacenters (most of which is based on VMware's technology) to Xen based cloud without any modifications
• simplify the process of moving workloads across many different clouds will make sure that the cloud ecosystem is federated. The fact that XCP is open source supporting open protocols and formats will ensure that the cloud ecosystem is open and federated

As expected, VMware came up with their own announcement at VMworld. Their announcement was more about talking than the walking. VMware announced the release of vCloud Express, directed towards the service providers to deliver Amazon EC2 like on-demand pay as you go services, and vCloud API, touting application mobility and cloud interoperability.

vCloud Express is a set of services built on top of vSphere and delivered to customers by the VMware service provider partners, which at this point of time includes Terremark, Hosting.com, Logica, Bluelock and Melbourne IT. Starting with an external vCloud environment, developers can deploy it on secure, reliable enterprise clouds inside their datacenters. Even though it is touted as an alternative to Amazon cloud, the very economics will dictate otherwise. I see this as a threat to providers like Skytap whose main differentiating element is their ability to move enterprise workloads seamlessly into their cloud labs. Even though you could hear the terms like interoperability and portability thrown along with vCloud initiative, it is all about playing within the VMware technological domain. There is enough merit to the noises made by pundits about vendor lock-in. In short, according to VMware, users could enjoy all the freedom as long as they do it on top of their own technologies. No wonder people like Richard Stallman call Cloud Computing as a trap for vendor lock-in.

VMware also announced the vCloud APIs which will help in deploying and managing applications in different cloud environments through a RESTful interface. The vCloud API enables the upload, download, instantiation, deployment and operation of vApps (application appliances in OVF format), networks and Virtual Datacenters (virtualized resources of compute power, storage and network). This API will make it very easy to move workloads from one cloud environment to another. In a way, this helps in the development of a federated cloud ecosystem. The version of API announced during VMworld is 0.8 (Technology Preview) and it is openly available (note: it is not open source) for consumption. vCloud API has also been submitted to the Distributed Management Task Force (DMTF), a standards body working to develop standards that enable interoperable IT management.

Not to be outdone by the news coming out of the two major virtualization vendors, Redhat, the open source giant who is propping up KVM over Xen after Microsoft friendly Citrix bought them. Actually, there are two announcement from the Redhat front. The first one is the integration of KVM at the kernel level in the recently released RHEL 5.4 OS. They are pushing KVM really hard. When their long support cycle for previous versions runs out in a few years, we can expect them to dump Xen completely. Redhat's marketshare in Hypervisor market is very negligible but this is good in the sense that there will be more choices and a wide array of choices is a good thing for users.

The second announcement is the release of Deltacloud which provides a portal for managing applications on many different code with many different APIs. They offer a framework that makes it easy for cloud providers to add their cloud to the Deltacloud common API. It is a REST based API with support for Amazon EC2 and RHEV-M. Pretty soon, they will be supporting VMware ESX and Rackspace. The best part of this API is the backwards compatibility across versions, providing long-term stability for scripts, tools and applications. The Deltacloud Portal is the UI to manage the varying set of Cloud APIs. Deltacloud is not only based on Open Standards but it is open source too.

Let me do a short recap of the above

• VMware touts openness about their cloud APIs but we are yet to their API. Even though they have approached the standards body, it doesn't mean anything till their API is widely tapped by the providers of other virtualization technologies
• Xen promises openness and open source but we have to wait fo some time to see them in action
• Redhat is the only one that touts openness and, also, open source. More importantly, they are the only ones who are offering the developers an interface to work with

With all the hoopla about standards, openness and open source, it is important to note the following

• Openness or open source doesn't imply standards. The main keyword here is adoption. When it comes to the issue of adoption, VMware is going strong on the enterprise side and Xen on the public cloud side.
  
• Vendor lock-in implies the absence of freedom and any talk about portability with the lock-in mechanism activated is just meaningless. Any attempts by VMware to stop interoperability by means of restriction will backfire

It remains to be seen how much VMware is really committed to create an open interoperable federated system of clouds. Whatever be the outcome of this game, one thing is clear. The future is an ecosystem of open and federated clouds. The action by these three virtualization vendors will go a long way in promoting such a future.