Main Governance Document#

The official version of this document, along with a list of individuals and institutions in the roles defined in the governance section below, is contained in The Project Governance Repository at:


The Project#

The Matplotlib Project (The Project) is an open source software project affiliated with the NumFOCUS Foundation. The goal of The Project is to develop open source software and deploy open and public websites and services for data visualization. The Software developed by The Project is released under a BSD (or similar permissive) open source license, developed openly and hosted in public GitHub repositories under the Matplotlib GitHub organization. Examples of Project Software include the Matplotlib library for data visualization and its associated extensions and dependencies. The Services run by the Project consist of public websites and web-services that are hosted under the domain.

The Project is developed by a team of distributed developers, called Contributors. Contributors are individuals who have contributed code, documentation, designs or other work to one or more Project repositories. Contributors are also known by the name “Matplotlib Development Team (MDT)” in the project license. Anyone can be a Contributor. Contributors can be affiliated with any legal entity or none. Contributors participate in the project by submitting, reviewing and discussing GitHub Pull Requests and Issues and participating in open and public Project discussions on GitHub, Discourse, Hackmd, Gitter chat rooms and mailing lists. The foundation of Project participation is openness and transparency.

For example, here is a partial list of the current Contributors to the main Matplotlib repository:


There are also many other Contributors listed in the logs of other repositories of the project. This also notably does not include contributions of items other than code, such as reporting and commenting on issues, so is only a subset of the individuals considered to be Contributors.

The Project Community consists of all Contributors and Users of the Project. Contributors work on behalf of and are responsible to the larger Project Community and we strive to keep the barrier between Contributors and Users as low as possible.

The Project is formally affiliated with the NumFOCUS Foundation (, a non-profit organization covered by section 501(c)(3) of the United States Internal Revenue Service code. NumFOCUS serves as its fiscal sponsor, may hold project trademarks and other intellectual property, helps manage project donations and acts as a parent legal entity. NumFOCUS is the only legal entity that has a formal relationship with the project (see Institutional Partners section below).


This section describes the governance and leadership model of The Project.

The foundations of Project governance are:

  • Openness & Transparency

  • Active Contribution

  • Institutional Neutrality

Project leadership was initially provided by the original author, John D. Hunter. Shortly before his passing in 2012, leadership was transferred to Michael Droettboom, who later invited Thomas A Caswell as a co-lead. Additional leadership has also been provided by a subset of Contributors, called Developers, whose significant or consistent contributions have been recognized by their receiving “commit rights” to the Project repositories. In general all Project decisions are made through consensus among the Developers with input from the Community.

While this approach has served us well, as the Project grows and faces more legal and financial decisions and interacts with other institutions, we see a need for a more formal governance model. Moving forward, the Project leadership will consist of a Project Leader, several Deputy Leads, and a Steering Council. We view this governance model as the formalization of what we are already doing, rather than a change in direction.

Project Lead#

The Project will have a Project Leader (PL), who is currently Thomas A Caswell. The PL has the authority to make all final decisions for The Project. In practice the PL chooses to defer that authority to the consensus of the community discussion channels, the Deputy Project Leads, and the Steering Council (see below). It is expected, and in the past has been the case, that the PL will only rarely assert their final authority. Because rarely used, we refer to PL’s final authority as a “special” or “overriding” vote. When it does occur, the PL override typically happens in situations where there is a deadlock in the Steering Council or if the Steering Council asks the PL to make a decision on a specific matter.

The PL is chair of the Steering Council (see below) and may delegate their authority on a particular decision or set of decisions to any other Council member at their discretion. The PL is responsible for ensuring that all SC activities that require a vote are properly documented.

The PL can appoint their successor, but it is expected that the Steering Council would be consulted on this decision. If the PL is unable to appoint a successor, the Steering Council will make a suggestion or suggestions to the Main NumFOCUS Board. While the Steering Council and Main NumFOCUS Board will work together closely on the PL selection process, the Main NumFOCUS Board will make the final decision. The NumFOCUS board may in extraordinary circumstances remove the PL from the project.

Steering Council#

The Project will have a Steering Council that consists of Project Contributors who have produced contributions that are substantial in quality and quantity, and sustained over at least one year. The overall role of the Council is to ensure, through working with the PL and taking input from the Community, the long-term well-being of the project, technically, financially, and as a community.

No Council Members may report to the same person through employment or contracting.

During the everyday project activities, council members participate in all discussions, code review and other project activities as peers with all other Contributors and the Community. In these everyday activities, Council Members do not have any special power or privilege through their membership on the Council. However, it is expected that because of the quality and quantity of their contributions and their expert knowledge of the Project Software and Services that Council Members will provide useful guidance, both technical and in terms of project direction, to potentially less experienced contributors.

The Steering Council and its Members play a special role in certain situations. In particular, the Council may:

  • Develop funding sources and determine how the money is spent (see Finance sub committee below).

  • Make decisions about the overall scope, vision and direction of the project.

  • Make decisions about strategic collaborations with other organizations or individuals.

  • Make decisions about the Services that are run by The Project and manage those Services for the benefit of the Project and Community.

  • Make decisions when regular community discussion doesn’t produce consensus on an issue in a reasonable time frame.

  • Grant or revok commit rights.

The steering council will be between 5 and 7 people including the PL. Being on the steering council is a responsibility, not a recognition of being a long-time contributor.

Council membership#

To become eligible for being a Steering Council Member an individual must be a Project Contributor who has produced contributions that are substantial in quality and quantity, and sustained over at least one year. Potential Council Members are nominated by existing Council members and voted upon by the existing Council after asking if the potential Member is interested and willing to serve in that capacity. The Council will be initially formed through PL nomination from the set of existing Developers who meet the above criteria.

When considering potential Members, the Council will look at candidates with a comprehensive view of their contributions. This will include but is not limited to code, code review, infrastructure work, mailing list and chat participation, community building, user and developer support, education and outreach, grant writing, and design work. We are deliberately not setting quantitative metrics (like “100 commits in this repo”) to avoid encouraging behavior that plays to the metrics rather than the project’s overall well-being. We want to encourage a diverse array of backgrounds, viewpoints and talents in our team, which is why we explicitly do not define code as the sole metric on which council membership will be evaluated.

When invited to join the Steering Council Contributors are commiting to serve for 2 years. At the end of the two years, with the consent of the rest of the council, may elect to rejoin the council. If they chose to not re-join the council the process above is used to recruit new members.

The Steering Council members, other than the PL, will serve in 2 equal classes whose terms are offset by 1 year. This will help preserve the continuity on the Steering Council over time.

A Steering Council member can step down at anytime. If a Council Member becomes inactive for a period of 2 months, they will be approached by the PL to see if they plan on returning to active participation. If not they will be asked to step down. If the Council Member indicates they intend to be active again but have not done so after 1 month the Council may vote to remove them.

If a Council Member leaves the council early they may be replaced, using the same process as above. Their replacement will join the same class and serve the remainder of the 2 years.

Each class can fluctuate between 2 and 3 members so long as the total council size (including the PL) is between 5 and 7. If a class gets too small, an additional member must be recruited.

All former Council members can be considered for membership again at anytime in the future, like any other Project Contributor. Retired Council members will be listed on the project website, acknowledging the period during which they were active in the Council.

The Council reserves the right to eject anyone, including the Council Members, from the project’s online spaces if they are deemed to be actively harmful to the project’s well-being, and attempts at communication and conflict resolution have failed by a super majority vote.

Conflict of interest#

It is expected that the PL, DPLs, and Council Members will be employed at a wide range of companies, universities and non-profit organizations. Because of this, it is possible that Members will have conflicts of interest. Such conflicts of interest include, but are not limited to:

  • Financial interests, such as investments, employment or contracting work, outside of The Project that may influence their work on The Project.

  • Access to proprietary information of their employer that could potentially leak into their work with the Project.

All members of the Council, PL included, shall disclose to the rest of the Council any conflict of interest they may have. Members with a conflict of interest in a particular issue may participate in Council discussions on that issue, but must recuse themselves from voting on the issue. If the PL has recused themselves for a particular decision, they will appoint a substitute PL for that decision.

Private communications of the Council#

Unless specifically required, all Council discussions and activities will be public and done in collaboration and discussion with the Project Contributors and Community through the normal communication channels. The Council will have a private mailing list that will be used sparingly and only when a specific matter requires privacy. When private communications and decisions are needed, the Council will do its best to summarize those to the Community after eliding personal/private/sensitive information that should not be posted to the public internet.


The Council can create subcommittees that provide leadership and guidance for specific aspects of the project. Like the Council as a whole, subcommittees should conduct their business in an open and public manner unless privacy is specifically called for. Private subcommittee communications should happen on the main private mailing list of the Council unless specifically called for or having external members.

NumFOCUS Subcommittee#

The Council will maintain one narrowly focused subcommittee to manage its interactions with NumFOCUS which will include external members.

  • The NumFOCUS Subcommittee is comprised of 4 persons who manage project funding that comes through NumFOCUS. It is expected that these funds will be spent in a manner that is consistent with the non-profit mission of NumFOCUS and the direction of the Project as determined by the full Council.

  • This Subcommittee shall NOT make decisions about the direction, scope or technical direction of the Project.

  • This Subcommittee will have 4 members, at least 2 of whom are also on the Steering Council and 1 of whom will be external to the Steering Council. No Subcommitee Member can report to the same person as any other member of the Subcommittee through employment or contracting work. This avoids effective majorities resting on one person.

Code of Conduct Subcommittee#

This committee should be between 3 and 7 people, at least one of whom is on the Steering Council and at least one who is not. This committee in responsible for fielding and addressing CoC reports that happen within our digital and physical spaces. They will maintain their own private mailing list and reporting address. Detailed policy on how to handle CoC will be documented elsewhere.

Deputy Project Leaders#

Deputy Project Leaders (DPL) have pre-delegated authority to make decisions within their area of responsibility. As with the PL, the DPL should strive to reach consensus before invoking their authority. Decisions by the DPL can be appealed to the PL, but the presumption is that the PL will defer to the DPL except in extraordinary circumstances. Disputes between DPLs will be settled by the PL.

DPLs are nominated by Steering Council members and appointed to a 1yr term (except for Release Manager) from their appointment date by a majority vote of the Steering council. At each 1yr term a DPL has the option to continue for another year or step down. The SC can remove a DPL via a super-majority vote..

At the discretion of the SC and PL a DPL position may not be filled in which case the responsibility devolves back to the PL. The SC can create a new DPL position, eliminate an unfilled DPL position, or change the description of a position by majority vote.

Any currently active Contributor is eligible to be considered for a DPL and an individual may hold more than one DPL simultaneously.

Project Specific Leads#

Matplotlib has a number of domain specific packages under it’s umbrella and hosted on the Matplotlib github organizations. These projects will each have their own Project Leader who can run the projects as they see fit consistent with the Matplotlib Code of Conduct.

If a project would like to be hosted on the Matplotlib organization on GitHub, they can petition the SC and be accepted by a simple majority vote. A project can leave the organization at anytime and can be removed from the organization by an 2/3 majority vote of the SC.

Institutional Partners and Funding#

The PL and Steering Council are the primary leadership for the project. No outside institution, individual or legal entity has the ability to own, control, usurp or influence the project other than by participating in the Project as Contributors and Council Members. However, because institutions are the primary funding mechanism for the project, it is important to formally acknowledge institutional participation in the project. These are Institutional Partners.

An Institutional Contributor is any individual Project Contributor who contributes to the project as part of their official duties at an Institutional Partner. Likewise, an Institutional Council Member is any Project Steering Council Member who contributes to the project as part of their official duties at an Institutional Partner.

With these definitions, an Institutional Partner is any recognized legal entity in the United States or elsewhere that employs at least one Institutional Contributor or Institutional Council Member. Institutional Partners can be for-profit or non-profit entities.

Institutions become eligible to become an Institutional Partner by employing individuals who actively contribute to The Project as part of their official duties. To state this another way, the only way for an Institutional Partner to influence the project is by actively contributing to the open development of the project, on equal terms with any other member of the community of Contributors and Council Members. Merely using Matplotlib Software in an institutional context does not allow an entity to become an Institutional Partner. Financial gifts do not enable an entity to become an Institutional Partner. Once an institution becomes eligible for Institutional Partnership, the Steering Council must nominate and approve the Partnership.

If an existing Institutional Partner no longer has a contributing employee, they will be given a one-year grace period for other employees to begin contributing.

An Institutional Partner is free to pursue funding for their work on The Project through any legal means. This could involve a non-profit organization raising money from private foundations and donors or a for-profit company building proprietary products and services that leverage Project Software and Services. Funding acquired by Institutional Partners to work on The Project is called Institutional Funding. However, no funding obtained by an Institutional Partner can override The Project PL and Steering Council. If a Partner has funding to do Matplotlib work and the Council decides to not pursue that work as a project, the Partner is free to pursue it on their own. However in this situation, that part of the Partner’s work will not be under the Matplotlib umbrella and cannot use the Project trademarks in a way that suggests a formal relationship.

In line with the sponsorship levels, an institution needs to provide at least:

  • 6 person-months/yr of paid work time for one or more Matplotlib maintainers or regular contributors to any Matplotlib team or activity

to be an Institutional Partner. In addition to the Sponsor acknoledgements as described in the sponsorship document, institutional partners can also:

  • Acknowledge their own funding sources on the Matplotlib websites, in talks and T-shirts.

Changing the Governance Documents#

Changes to the governance documents are submitted via a GitHub pull request to The Project’s governance documents GitHub repository at matplotlib/governance. The pull request is then refined in response to public comment and review, with the goal being consensus in the community. After this open period, a Steering Council Member proposes to the Steering Council that the changes be ratified and the pull request merged (accepting the proposed changes) or proposes that the pull request be closed without merging (rejecting the proposed changes). The Member should state the final commit hash in the pull request being proposed for acceptance or rejection and briefly summarize the pull request. The full Steering Council must vote and at least 2/3 of the votes must be positive to carry out the proposed action (fractions of a vote rounded up to the nearest integer). Since the PL holds ultimate authority in The Project, the PL has authority to act alone in accepting or rejecting changes or overriding Steering Council decisions.