Part of what makes this interesting is that OSv is a single-user, single-application OS layer than runs either on KVM or XEN. To quote one of the authors:
Avi: The traditional OS supports multiple users with multiple applications running on top. OSV doesn't do any of that. It trusts the hypervisor to provide the multi-tenancy and it just runs a single one. We do a smaller job and that allows us to do it well and allows the administration of that system to be easeir as well because there's simply less to administer.
From the web site:
OSv reduces the memory and cpu overhead imposed by traditional OS. Scheduling is lightweight, the application and the kernel cooperate, memory pools are shared. It provides unparalleled short latencies and constant predictable performance, translated directly to capex saving by reduction of the number of OS instances/sizes.
I'm excited to check this out since you can run it easily in an existing Linux environment. I'd really like to see how ElasticSearch performs on OSv. You can find out more information on their site, osv.io.