Unikernels are application images that contain only the bare minimum amount of code necessary to make an application run. They're similar to containers in that they pack applications into portable, standalone environments, but unikernels take things a step further by cutting out as much overhead as possible. They also generally contain a complete operating system, rather than relying on a host OS, as containers generally do.
If you haven't yet heard much about unikernels, you're not alone. The only big news item in this area so far was Docker's acquisition of Unikernel Systems, a small company working on unikernel technology, back in January 2016. Since then, Docker has kept its cards close regarding its unikernel plans, and few other companies have announced products in this space.
But EMC's announcement this week of the availability of UniK is a sign that unikernel solutions are likely to become a larger part of the container and microservices conversation soon. EMC is pitching the product as an easy way for developers to leverage microservices in order to package software for the cloud or IoT environments.
"UniK enables software developers to compile applications into different unikernels creating extremely lightweight, efficient application instances," the company said. "These single-purpose images can then be deployed on hypervisors such as VMware vSphere or KVM with application platforms such as Cloud Foundry, Docker and Kubernetes."
EMC also appears to hope to engage the DevOps market with UniK, which integrates with open source code management and build platforms.
UniK is available on GitHub as open source under an Apache 2.0 license.
At this point, it seems quite early to expect major adoption of unikernel solutions. Developers still have to work through some big issues, like storage, in the same way that Docker, CoreOS and other companies have done to make containers realistic for production environments. But there's little doubt that these challenges will be solved in time, and that unikernels like the ones UniK promises to create will assume a significant role in the cloud and IoT.