When we open sourced Docker, we had considerable experience running openvz in production, as well as migrating to lxc - a miserable experience in the early days because the paint was still so fresh. To my knowledge we were the very first production deployment of managed databases and multi-tenant application servers on lxc, back in 2010.
It's a common misconception that Docker was a naive reinvention of, or a thin wrapper around, pre-existing technology like solaris zones or lxc. In reality that is not the case. Those technologies were always intended as alternative forms of virtualization: a new way to slice up a machine. Docker was the first to use container and copy-on-write tech for the purpose of packaging and distributing applications, rather than provisioning machines. Before Docker, nobody would ever consider running a linux container or solaris zone on top of a VM: that would be nonsensical because they were considered to be at the same layer of the stack. Sun invented a lot of things, but they did not everything :)