Docker is a popular OS level virtualization LXC, but what is exciting here,
- Portable - single file (I believe)
- Low overhead - should run inside of my Ubuntu KVM
- Has become cross-platform (in a sense)
- Works with the vanilla Linux kernel (no patching).
References
Discusses security - https://blog.docker.com/2013/08/containers-docker-how-secure-are-they/