FWIW: The two companies that contributed the most to the namespace code in the upstream Linux kernel (that Docker uses) were Parallels and Google, both of which know a lot about containers at Scale. For those that don't know, Parallels wrote virtuozzo.
I also suspect that it won't take super long for container technologies like Docker to take over OpenVZ/Virtuozzo if not only for projects like Kubernetes, which is backed by Google, and is the basis for commercial PaaS offerings such as Openshift v3 from Redhat. Virtuozzo is great tech, but using it for a new buildout seems like a bad idea for the forseeable future. Docker is not as good, but will be soon, and is supported out of the box on every modern distribution.
(from linux.git):
$ git log --pretty=oneline --no-merges --author='@parallels.com' | wc -l 695
I also suspect that it won't take super long for container technologies like Docker to take over OpenVZ/Virtuozzo if not only for projects like Kubernetes, which is backed by Google, and is the basis for commercial PaaS offerings such as Openshift v3 from Redhat. Virtuozzo is great tech, but using it for a new buildout seems like a bad idea for the forseeable future. Docker is not as good, but will be soon, and is supported out of the box on every modern distribution.