Docker is my containerisation choice, I've been using it on and off since 2014.
It's a technology that allows you to run multiple lightweight Linux-based environments (containers) that are separated from each other in a way similar to virtual machines.
Current Version: 18.06.1-ce (2018-08-21)
There are a few limitations compared to classical VMs, but also quite a few advantages.
It's possible to find and install Docker on almost any recent Linux distro, and even though core technology depends on Linux native elements like namespaces, there are successful attempts to port Docket to different operating systems – like MacOS. It should be noted though that such "ports" are imposing limits on the Docker technology, so for native best experience you really must run Docker on Linux.
Docker for CentOS distribution is available for free Community Edition (CE) and as a subscription in Enterprise Edition (EE) and can be installed on bare metal or cloud infrastructure.
It all started with the free Community Edition (CE) of Docker – this option is still available today and still costs nothing to download and to use.
Enterprise Edition (EE) of Docker is an offering that provides extended software support, priority technical support and many other options of getting the most of the Docker technology in a commercial environment.