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I haven't seen much OpenVZ in production, nor heard of it used in more than some niche cases. It's out there, to be sure, but like all container tech it's not yet ascendant. Try this series of 4 articles for my look at containers, including OpenVZ:

http://www.theregister.co.uk/2014/11/28/docker_part_1_the_history_of_docker/

http://www.theregister.co.uk/2014/12/01/docker_part_2_the_libcontainer_evolution/

http://www.theregister.co.uk/2014/12/02/docker_part_3_containers_versus_hypervisors/

http://www.theregister.co.uk/2014/12/04/docker_part_4_prognostication_microsoft_and_the_red_wedding/