The Open Container Initiative has just launched a new project as part of its mission to create open industry standards around software container formats and rules.

The group said Monday it wants to standardize container image distribution based on Docker Inc.’s Registry v2 protocol in order to further interoperability within the container ecosystem.

Software containers are used to isolate applications so they can be built once and run on any hardware or operating system. Most developers use the Docker Registry to store container images, which are data pieces that make up a fully functioning software container. The Docker Registry v2 protocol, the most common mechanism used to push and pull container images into and out of runtime environments, has been used more than 40 billion times so far.

So popular is the Docker Registry protocol that it has become the de facto standard platform for pulling container images, developers explained in the project’s release notes on GitHub. “There is and will be use cases for alternate methods and the future will likely hold creative ways to push, fetch and share container images, but right now this promotion serves to acknowledge by the OCI the current industry standard of distributing container images,” the developers noted.

The new standard, which is supported by just about every major cloud technology company, including Amazon Web Services Inc., Google LLC, IBM Corp. and Microsoft Corp., is said to be an important step in standardizing on software containers.

Previously, the OCI has standardized on both the container image format and container runtime. Those specs support the portability of containers across different operating systems and platforms. Companies can use the specifications to develop, package and sign application containers, then run them on a variety of container engines.

The OCI said a solid, common distribution specification paired with conformance testing helps ensure interoperability across the entire ecosystem.

“Basically, as long as images follow this specification, it should enable anyone to build tools that will work with the images and have the resulting images be compatible with any compliant runtime,” said Joe Brockmeier, Red Hat’s senior evangelist for Linux Containers.

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