Wow has it been a whirlwind over the last ten years in the virtualization space. Where once Xen and then KVM sat on the pedestal, the baton has been passed to the projects revolved around containers. Names like Docker, Kubernetes and Mesos are most often mentioned. As is generally the case in the FLOSS arena, evolution is a constant. Therefore, if one is in the DevOps arena, it is time to familiarize yourself with containers if you have not already done so.

First of all, let's examine the virtual machine space. VMware, the elephant in the room, still commands a lot of attention. After all, it is a publicly traded company with billions in revenue. A lot of companies utilize VMware for its virtualization needs, and the numbers bear that out. Essentially, it is still the leader in the clubhouse. But, its lead is not what it once was. Over the 15 months examined, whether it is VMware, ESX/ESXi or vSphere, all have been on the decline. Each of those keywords within the listings has seen a 20-30% slide. And, more concerning is the fact that they have been falling at a fairly even pace.
Next up, two prominent projects in the FLOSS arena that perhaps have lost a little of their luster. I am speaking specifically of Xen and KVM. We all watched Xen turn into a professional company, Xensource, and then was acquired by Citrix. KVM followed a similar pattern. What started out as KVM turned into its professional entity, Qumranet, albeit briefly, before it was eaten up by Red Hat. Both Xen and KVM have seen declines during the time period, although Xen is deteriorating at a faster clip. In each of their defense, they were both purchased by large firms, so perhaps the numbers are lost in translation as a result. However, for this particular exercise, we must focus on keywords, and in this case the results are what they are.

Demand for Virtualization Technologies

As some fall, others rise. That is the case with containers. For ease, let's start with Docker. After all, it is considered the pioneer and is the biggest player in the container space. Much like Xen and KVM before it, it too has been developed into its own company, Docker Inc. Too early to tell if it will follow the same fate as those two predecessors. However, we can not worry about that at this point. The more important piece is the traction it has gained. Its rise has been phenomenal. In a short 15 month period, its growth is 3x. It is one of the fastest growing mainstream FLOSS projects we have analyzed. Truly amazing! In fact, it is asked for by nearly half as many employers that ask for VMware. That says quite a lot when you consider the length of time each has been around.

Not to be forgotten is Kubernetes. Originally an in-house Google project, it has since been donated to the Cloud Native Computing Foundation. While Docker's growth rate of 3x seems incredible, and indeed it is, Kubernetes has had a growth rate of 7x. Astonishing! Perhaps the largest that we have seen in all the numbers we have researched.

Finally, Mesos. Apache Mesos is another piece of software in the container space on the rise. While not quite keeping up with the likes of Docker and Kubernetes, it has still commanded a growth rate of 2x over the time period examined. Surely nothing to sneeze at.

Demand for Containerization Technologies

So, where does this leave us? Is the virtual machine space giving way to containers? In essence, yes. The numbers indicate that to be the case. Each of the popular container projects analyzed is currently outpacing its counterparts in the virtual machine space. And, with the Linux Foundation forming the Open Container Initiative (OCI) to establish open industry standards around container formats, its existence is cemented. As a result, is the traditional virtual machine space doomed? At first glance, one might tend to think it is headed in that direction. However, much like in other areas of technology, there is always a lot of dated software that large corporations run that does not translate well to the container space. Therefore, virtual machines are not going away anytime soon.