rkt
rkt is a pod-native container engine for Linux
...Composability: rkt is designed for first-class integration with init systems (like systemd, upstart) and cluster orchestration tools (like Kubernetes and Nomad), and supports swappable execution engines. Open standards and compatibility: rkt implements the appc specification, supports the Container Networking Interface specification, and can run Docker images and OCI images. Broader native support for OCI images and runtimes is in development.