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CNCF Sandbox Overview

CNCF Sandbox

The CNCF Sandbox is the entry point for early stage projects and has four goals:

  • Encourage public visibility of experiments or other early work that can add value to the CNCF mission and build the ingredients of a successful Incubation level project
  • Facilitate alignment with existing projects if (and only if) this is desired
  • Nurture projects (e.g. via CNCF Service Desk requests)
  • Remove possible legal and governance obstacles to adoption and contribution by ensuring all projects adhere to CNCF legal, code of conduct and IP Policy requirements

This document describes the Sandbox and provide clarity on what Sandbox projects stand for.

What is the CNCF Sandbox

Sandbox projects should be early-stage projects that the CNCF TOC believes warrant experimentation. The Sandbox should provide a beneficial, neutral home for such projects, in order to foster collaborative development. We aspire to make the Sandbox the preferred path for early-stage projects to enter the CNCF. More mature projects can continue to jump directly to Incubation, but as the cloud-native ecosystem grows, we expect to see proportionally more early-stage projects.

Early Stage

When we say that Sandbox projects are "early stage" this covers the following examples:

  1. New projects that are designed to extend one or more CNCF projects with functionality or interoperability libraries.
  2. Independent projects that fit the CNCF mission and provide potential for a novel approach to existing functional areas (or are an attempt to meet an unfulfilled need)
  3. Projects commissioned or sanctioned by the CNCF, including initial code for CNCF WG collaborations, and "experimental" projects
  4. Any project that realistically intends to join CNCF Incubation in future and wishes to lay the foundations for that

Caveat Utilitor

The CNCF hopes that all early stage projects will achieve the success they desire. And the organisation will help as appropriate. But certain caveats must be stated nonetheless.

End users should treat early stage projects with care. It is expected that some Sandbox projects may fail. They may never move to the next maturity level. While many early projects are safe to try out, users must exercise their own judgment. Some projects may be alpha quality software. There is no guarantee of production readiness, users, or professional level support. Where projects enjoy the public support of one or more professional software organisations, those may be seed stage. In short: The CNCF Operating Principle about "no kingmakers" is of special importance in the Sandbox.

Routes out of the Sandbox

There are several possible next steps for a project in Sandbox:

  • If it achieves sufficient momentum and maturity it can apply for Incubation status
  • Based on alignment with another project, it might make sense to merge with or become part of another project within the CNCF. This would be done based on a consensus between project maintainers and the TOC that this is best for both projects.
  • Some projects and experiments may fail, or otherwise reach a state where they should be moved into the Archive

Sandbox Governance and Benefits

Advantages of Sandbox vs non-Sandbox for new projects

CNCF will remain fair and open to all projects no matter what their initial provenance. Should a project apply for CNCF Incubation, the TOC will use the same criteria regardless of origin. This means the TOC will not discriminate in favour of Sandbox projects vs. non-Sandbox projects.

Therefore the advantages of being in the Sandbox apply prior to application for Incubation, ie.:

  1. That a project has a legally neutral home that is stable and known

  2. And that a project may attain Incubation-level success faster:

    1. Due to public visibility and association with the CNCF mission
    2. Through alignment with other CNCF projects (if and only if desired)
    3. Via CNCF Service Desk etc.
  3. The CNCF will help projects adopt good principles of governance

Neutral Home

A neutral home for your project increases the willingness of developers from other companies and independent developers to collaborate, contribute, and become committers. Neutrality requires that projects contribute their trademark to CNCF so that:

  • No company is favored over any other
  • CNCF ensures project governance is transparent and fair for everyone.

Clarifying Marketing Expectations

All open source projects in some sense enjoy a level of promotion from community, user enthusiasm, sponsoring organisations and so on. Please note that in this section we discuss marketing as a measurable financial investment into CNCF projects from the CNCF marketing budget and staff.

To date the CNCF has invested in marketing to educate users and grow awareness of cloud native purpose and benefits, to foster community, and to accelerate production use of projects. These investments fall into at least three types:

  • Developer community support: hangouts, meetups, events and (some) conferences
  • Digital marketing: help with online content, interactive tutorials, webinars, and social
  • Product marketing: conference promotion, landscape, certification, case studies, AR/PR

Since the Sandbox is for early stage, sandbox projects will receive minimal marketing support from the foundation. The Sandbox group as a whole may be promoted from time to time.

The CNCF will lean towards developer community support and the CNCF service desk, to help discovery and initial steps towards CNCF Incubation. There will only be limited CNCF investment in Digital and Product marketing for individual Sandbox projects, and CNCF-funded content should be factual and informative.

Some key points:

  • Sandbox projects will be listed separately from other CNCF projects (
  • They will not be prominently listed at our events or issued a press release
  • Reviewed on an annual basis; submit a report to the TOC for review
  • CNCF Sandbox projects can stay in the sandbox indefinitely

Application into Sandbox

Projects apply through the Sandbox Repo's Issue Form. More information on this process is found on the main Sandbox repo page. Frequency of reviews can be found on the repo's README under "Frequency".

Project onboarding

Once the TOC decides to accept your project with an official vote, a list of tasks will be generated for submitters to work on. Look for tags project onboarding and sandbox to see examples from previous projects

Annual review

Once in the Sandbox, projects are subject to an Annual Review.