Nanos: a kernel designed to run one application in a virtualized environment

Nanos is a new kernel designed to run one and only one application in a virtualized environment. It has several constraints on it compared to a general purpose operating system such as Windows or Linux – namely it’s a single process system with no support for running multiple programs nor does it have the concept of users or remote administration via ssh.
↫ Nanos GitHub page

The project has a website with more information and instructions, and the code’s on GitHub.