DRAFT – FOR REVIEW
This content is subject to review by the IPMC and the project community. This material was developed by individuals outside the individual podling communities, who may view events differently than those directly involved. Some content was AI-generated and may contain errors; however, the material has been reviewed and verified by a human for accuracy. It is provided for training and discussion purposes and may contain minor simplifications or adjustments for clarity.
The ASF Incubator Case Studies collect real lessons from podlings across the Incubator. Each case study groups together projects that faced similar challenges and shows how mentors and communities addressed them.
These case studies are intended as reference material for mentors, PPMC members (Podling Project Management Committees), and contributors who want to understand how communities have grown and matured during incubation.
Each case study includes:
You can use these pages to:
Together, these examples build a shared record of ASF experience in community development.
Not every project at Apache is meant to last forever, and that is normal. Graduation, withdrawal, and retirement are all valid outcomes of open development.
Podlings and their mentors sometimes face hard choices when activity slows, goals are met, or the wider ecosystem moves on. The key is to handle each transition openly, respectfully, and with clear communication.
For mentors, this case study shows how to recognise when a community has reached its natural transition point and how to guide it toward closure or renewal. For PPMC members, it highlights how transparent discussion, timely decision-making, and documentation protect the project’s reputation and preserve lessons learned.
This case study draws on five real examples: MXNet, Mesos, Wave, Blur, and Zipkin. Each shows a different kind of transition, from healthy retirement after success to early withdrawal when the ASF model was not the right fit.
Think about your own podling.
If these questions raise uncertainty, these examples can help you think through healthy ways to close, graduate, or move on.
The case studies highlight how past projects managed transitions with openness and respect. You can use them when preparing graduation or withdrawal discussions, supporting reporting cycles, or reflecting on long-term sustainability.
They can help you:
These examples show how different podlings reached the end of their lifecycle, each in its own way.
Their experiences illustrate how to manage transitions openly, maintain respect, and capture what was learned.
MXNet entered incubation in January 2017 and graduated in September 2022.
It began at the University of Washington and later gained strong AWS sponsorship.
It delivered multiple ASF-compliant releases and graduated in 2022.
However, most development remained within one company, and contributor diversity did not expand.
As interest waned, the ASF Board and community agreed to retire it in 2023.
Key Point: Graduation does not guarantee sustainability.
What Mentors and PPMCs Can Do: Track post-graduation activity and help ensure leadership and contributions remain diverse.
Mesos entered the Incubator in December 2010 and graduated in July 2013
It became critical infrastructure for major companies such as Twitter and Airbnb.
It thrived for years before Kubernetes changed the industry landscape.
As interest declined, the project was retired to the Attic in 2021.
Key Point: Even successful projects can naturally come to a natural conclusion as technology evolves.
What Mentors and PPMCs Can Do: Encourage open discussion about relevance and long-term plans before activity declines.
Wave entered incubation in December 2010 and retired in January 2018.
Google donated “Wave in a Box” to the ASF in 2010.
Despite enthusiasm, most activity remained among a few original developers.
Few new committers joined, and mailing list activity was minimal.
Key Point: Stalled incubation should lead to honest review and, if needed, closure.
What Mentors and PPMCs Can Do: Support transparent self-assessment and avoid indefinite incubation.
Blur entered incubation on July 2012 and retired in June 2017.
It was a promising search engine built on Lucene.
However, community growth and releases remained limited.
After repeated IPMC discussions, it was retired.
Key Point: Prolonged inactivity signals the need for respectful closure.
What Mentors and PPMCs Can Do: Encourage early reflection when participation remains low.
Zipkin entered incubation in August 2018 and withdrew in June 2019.
The podling completed Apache Incubator source releases in 2019 and also maintained development activity in the existing OpenZipkin GitHub organization.
The community voted to withdraw from the Incubator in 2019, and development continues successfully outside Apache.
Key Point: Withdrawal can be a positive and transparent outcome.
What Mentors and PPMCs Can Do: Help communities make informed, respectful decisions about whether the ASF model is the right fit.
Across these examples, the shared lesson is that transitions are part of the open-source lifecycle. Handled with transparency and documentation, they strengthen ASF culture by showing that success means learning, not just survival.
| Pattern | What It Looks Like | Why It Matters |
|---|---|---|
| Transparent transition discussions | Public proposals for graduation, withdrawal, or retirement | Builds trust and closure |
| Declining activity recognised early | Mentors or PPMC initiate honest reflection | Prevents confusion or blame |
| Respectful retirement | Community acknowledges achievements and lessons | Preserves dignity and institutional memory |
| Continued value outside ASF | Code or ideas live on elsewhere | Shows ASF’s support for open ecosystems |
| Post-graduation follow-up | Mentors or former IPMC members stay engaged | Strengthens continuity and support |
These patterns show that the ASF model values how transitions are handled as much as the technical results.
Early recognition allows respectful closure before frustration builds.
This table helps mentors and PPMCs discuss project direction and sustainability.
It is a self-review tool, not an ASF checklist.
| Area | What to Ask | Signs of Healthy Progress | Signs That Need Attention |
|---|---|---|---|
| Sustainability | Is development continuing at a healthy pace? | Regular releases and new contributors | Long periods without visible progress |
| Engagement | Are mentors and PPMC active on lists? | Discussion and decisions are visible | Only occasional or one-person posts |
| Relevance | Does the community still meet user needs? | New users or adopters appear in discussions | Decline in adoption or industry focus |
| Decision Making | Are transition options discussed openly? | Clear proposals for graduation or closure | Avoidance or private conversations |
| Documentation and Handoff | Are lessons being recorded? | Public closure summary or retrospective | Unclear or undocumented ending |
| Transition | Description | Typical Approval | Key ASF Guide |
|---|---|---|---|
| Graduation | Project has met community and governance maturity expectations and becomes a Top-Level Project | Vote by the IPMC and Board | Podling Graduation Guide |
| Withdrawal | Podling decides Apache is not the right home and ends incubation voluntarily | Vote by the podling and IPMC | Podling Retirement Guide |
| Retirement | IPMC and Board conclude that the podling or TLP is inactive or unsustainable | IPMC and Board approval | Project Maturity Model |
This material can also be used in joint mentor–PPMC discussions or post-retirement retrospectives.
Recognise natural completion
When goals are met or interest fades, discuss the project’s future openly. (Mesos)
Support transparent decisions
Keep all transition conversations on dev@ and summarise outcomes for the community. (MXNet)
Document lessons learned
Publish a short retrospective or closure note to preserve insight. (Wave)
Respect withdrawal choices
Help communities that decide Apache is not the right fit to leave gracefully. (Zipkin)
Prevent indefinite incubation
If progress stalls for many months, propose a structured review and possible closure. (Blur)
Encourage post-graduation self-checks
Follow up six months after graduation to assess diversity and engagement. (MXNet)
Acknowledge achievements
Celebrate contributions even when retiring; every effort builds the ASF’s shared knowledge. (Mesos, Wave)
Mentors and PPMCs should reflect lifecycle discussions transparently in podling reports.
The IPMC looks for clear evidence of open decision-making, documented outcomes, and learning from experience.
When preparing for graduation or closure, describe specific community signals rather than general statements.
Relevant ASF Resources
These examples help the IPMC and Board understand transitions clearly and maintain trust in the ASF process.
Open development includes beginnings and endings.
Graduation, withdrawal, and retirement each demonstrate transparency and autonomy.
Communities should be free to conclude their work with dignity and clarity.
Mentors and PPMCs support that by ensuring decisions are visible, records are complete, and achievements are recognised.
Handled this way, every transition strengthens the ASF’s culture of openness and shared learning.
The ASF preserves each project’s public record in perpetuity so future contributors can learn from its history.
This case study summarises information from ASF public mailing lists, podling reports, and status pages. It was written from the perspective of observers outside the individual podling communities. Community members may hold differing views on events or timelines, and minor simplifications may be made for clarity or training purposes. It includes historical information drawn from public ASF sources and does not represent the current state of any project mentioned. This content may contain errors or omissions due to AI-generated elements. However, the material has been reviewed and verified by a human for accuracy. These factors do not reduce its value as a reference for understanding patterns of incubation and global collaboration.