Docker 17.03.2-ce Docker is an open platform for distributing software application in containers. It utilizes operating system-level virtualization for process and full resource isolation through cgroups, capabilities, SELinux, AppArmor, netfilter, and Linux kernel namespaces. Its libcontainer is based on libvirt and lxc. Docker Engine is the application and environment packaging tool. And Docker Hub is a cloud service for sharing prepackaged containers.