The Open Container Initiative Runtime Specification is a standards document that defines how container runtimes should operate on operating system processes and applications.
The specification addresses the need for a common interface between container orchestration systems and the low-level runtimes that execute containers. It provides a detailed contract covering bundle structure, configuration files, and runtime behavior across different platforms. The specification enables interoperability by allowing any compliant runtime to execute bundles created by any compliant builder, and allows runtimes to be swapped without changing higher-level tooling.
Application bundle builders, hook developers, and runtime developers are the primary audiences. Bundle builders use the specification to create portable container configurations that include executable details, mount points, lifecycle hooks, and platform-specific settings like Linux namespaces and cgroups. Hook developers extend runtime functionality by integrating external applications at container lifecycle points. Runtime developers implement the specification to create runtimes that execute OCI-compliant bundles on specific platforms. The specification is foundational infrastructure rather than an end-user tool; adoption means building tooling that conforms to it or implementing a runtime against it.
The project operates through structured governance with regular contributor and maintainer meetings, a mailing list for design discussions, and chat channels for community interaction. Contributions are expected to be discussed on the mailing list before substantial changes are submitted, ensuring design validation before implementation. The project maintains documentation on code of conduct, style conventions, and implementation examples alongside the core specification document.
