Docker Engine-Community – free Docker

The open source version of Docker is called Docker Engine-Community and it is distributed under the Apache 2.0 licence. Sometimes referred to as free Docker, this version is self-and community-supported. Docker has two packaging schemes:

• Docker Engine-Community for x86 64-bit desktop architectures for Mac and Windows 10 Pro+
• Server CE for targeting CentOS, Debian, Fedora, and Ubuntu Linux distributions

In addition to the platform packaging, Docker Engine-Community comes with two channels. It is important to note that as of Docker Engine-Community version 18.09, the stable channel will release on a six-month cadence and the edge channel will be replaced with a nightly build:

• Stable channel: General availability code is released through this channel after being thoroughly tested.
• Edge channel for desktop platforms: Monthly release of prerelease code that is in various stages of testing. 
• Nightly channel: Fresh code is released here! Subsequently, cool new features show up here first, but this code base is not completely tested and should not be used for production. Also, if your developers use the edge channel (or run with the —experimental flag) on their workstations, you will need to be very careful to avoid the works on my machine scenario! Take care to ensure new code is not relying on unreleased GA or experimental features that will work on the developer's workstation, but will break later as images and/or configurations move through the pipeline. 

You may consider having a development cluster where developers deploy their code on a Docker infrastructure that matches production versions. If a dev cluster is available, developers should always deploy to dev before their code is checked in, to ensure no builds are broken.