Graduated and incubating projects are considered stable and used successfully in production.
Project maturity levels
CNCF projects have a maturity level of sandbox, incubating, or graduated, which corresponds to the Innovators, Early Adopters, and Early Majority tiers of the Crossing the Chasm diagram. The maturity level is a signal by CNCF as to what sorts of enterprises should be adopting different projects. Projects increase their maturity by demonstrating their sustainability to CNCF’s Technical Oversight Committee: that they have adoption, a healthy rate of changes, and committers from multiple organizations; have adopted the CNCF Code of Conduct; and have achieved and maintained the Core Infrastructure Initiative Best Practices Badge. Full details are in the Graduation Criteria.