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History ​

Origin ​

In 2016 Kubernetes introduced the Container Runtime Interface (CRI), a plugin boundary that lets the kubelet swap container runtimes without recompiling. CRI-O began as the project to fill that boundary with a minimal, Kubernetes-only runtime. It started under the name OCID, led by Red Hat developers in the Kubernetes incubator alongside Google contributors (CNCF graduation announcement, Red Hat blog). The GitHub repository was created on 2016-09-09.

The o in the name and the early pod tooling came from libpod, which lived inside CRI-O and provided a Docker-CLI-like experience. That code later grew into Podman, and CRI-O narrowed to the CRI itself (CNCF announcement).

Timeline ​

YearMilestone
2016Kubernetes adds the CRI; the project starts as OCID, then renames to CRI-O (CNCF)
2019CNCF TOC accepts CRI-O as Incubating on 2019-04-08 (CNCF)
2023CRI-O graduates from the CNCF on 2023-07-19 (CNCF)
2026Released line at v1.36.1 (2026-06-03); main reports 1.37.0 (internal/version/version.go:6)

How it evolved ​

When the CNCF accepted CRI-O as Incubating in 2019, its maintainers came from Red Hat, Intel, and SUSE, and early users included Lyft, Red Hat, and SUSE (CNCF). During incubation the project shipped 11 minor versions, around 100 patch releases, and more than 4000 commits, reaching tens of thousands of clusters (CNCF, InfoQ).

Graduation in 2023 required the usual CNCF maturity work: updated governance, a Code of Conduct, a security disclosure process, and a third-party security audit by Ada Logics coordinated with the CNCF and OSTIF, plus documented end users and end-user interviews (CNCF).

The defining design constant has been scope. CRI-O tracks Kubernetes version for version: a CRI-O 1.x release targets Kubernetes 1.x. The README still draws the boundary explicitly, delegating execution, images, storage, and networking to other components rather than absorbing them (README.md:102-119).

Where it stands now ​

CRI-O releases on the Kubernetes cadence, maintaining recent minor lines (ReleaseMinorVersions = {1.36, 1.35, 1.34} per the recon notes). The latest released tag at the pinned commit is v1.36.1 (2026-06-03), and main is on the 1.37.0 development line (internal/version/version.go:6). It is a CNCF Graduated project (CNCF projects).