"An Atomic Host is a lean operating system designed to run Docker containers, built from upstream CentOS, Fedora, or Red Hat Enterprise Linux RPMs. It provides all the benefits of the upstream distribution, plus the ability to perform atomic upgrades and rollbacks"
Just returned to suggest the same thing. Perhaps the difference being that Ubuntu Core doesn't seem to be built exclusively for Docker, but rather to work with it and it's competitors.
"An Atomic Host is a lean operating system designed to run Docker containers, built from upstream CentOS, Fedora, or Red Hat Enterprise Linux RPMs. It provides all the benefits of the upstream distribution, plus the ability to perform atomic upgrades and rollbacks"