Open Container Project
As the different container technologies are being developed, there is a necessity of having a standard container format in order to provide interoperability and define the standard for the containers. In order to achieve this, the CoreOS team started working on a container standardization mechanism called App Container to define the standard container image format, runtime environment, and discovery protocol, to work toward the goal of a standard, portable shipping container for applications.
Meanwhile, the Open Container Project (OCP) was formed by a large group of industry leaders to define the standard. The Open Container Project is hosted under Linux Foundation. CoreOS App Container also contributes to OCP and the latest specification of the OCP project can be found at the following link: https://github.com/opencontainers/specs