Rocket

Docker is no longer the only container available on Linux. CoreOS developed a new container technology called Rocket, which is quite different from Docker in architecture. Rocket does not have a daemon process; Rocket containers (called App Containers) are created as child processes to the host process, which are then used to launch the container. Each running container has a unique identity. Docker images are also convertible to App Container Image (a naming convention used for Rocket images). Rocket runs on a container runtime called App Container Runtime.