EzMaster is a non-technical docker backoffice tools for non-IT administrators. It aims to manage applications and instances. One instance of an application is a docker packaged software having its own config and its own data. Each instance is a docker container, is isolated and independant, and can be stopped or started easily on demand. Applications are "ezmasterized" docker images, they can be easily downloaded from dockerhub.
Why are you here? you are insterested by ezmaster because you are a end-user, a developer, or an op guy?
You could also check all the EzMaster available versions at the changelog page.