Docker gave away its container format to stop a standards war

Container formats multiplied, and rival specs like CoreOS's appc risked splitting developers into incompatible worlds.

In June 2015 Docker and a broad coalition created the Open Container Project under the Linux Foundation, and Docker donated its image format and runtime as the cornerstone.

Neutral, open governance meant the standard was not controlled by one company, so the ecosystem could build on it together.

Donate the de facto format to neutral open governance

Neutral governance meant no single company could steer the standard for its own advantage.

Backing the de facto format preserved the installed base and the millions of containers already built.

Merging appc and the Docker format into one spec removed the risk of two incompatible container worlds.

The Linux Foundation's neutrality drew a wide vendor coalition to agree quickly.

The owner of a dominant format can keep it dominant by giving it to a neutral body, turning the threat of fragmentation into a moat.

The Open Container Initiative's image and runtime specs became the shared standard across Docker, Kubernetes and most container tooling; the container ecosystem grew without a format split.