[evol262]

Docker is application containerization.

While Docker is built on top of libcontainer and cgroups (used to be LXC), traditional containers, including LXC and zones, start init and enough services to look like a "normal" system. You can still use rc.local to manage applications if you want to, I guess.

Docker is a build system for containers which run /bin/foo as PID1, with no services, no ssh, and no init (which presents other problems reaping children, handling sigterm, etc). It's containerization for application virtualization.