SKIP 1 — scikit-image governance and decision-making#


Juan Nunez-Iglesias <>


Stéfan van der Walt <>


Josh Warner


François Boulogne


Emmanuelle Gouillart


Mark Harfouche


Lars Grüter


Egor Panfilov














The purpose of this document is to formalize the governance process used by the scikit-image project, to clarify how decisions are made and how the various elements of our community interact.

This is a consensus-based community project. Anyone with an interest in the project can join the community, contribute to the project design, and participate in the decision making process. This document describes how that participation takes place, how to find consensus, and how deadlocks are resolved.

Roles And Responsibilities#

The Community#

The scikit-image community consists of anyone using or working with the project in any way.


A community member can become a contributor by interacting directly with the project in concrete ways, such as:

among other possibilities. Any community member can become a contributor, and all are encouraged to do so. By contributing to the project, community members can directly help to shape its future.

Contributors are encouraged to read the contributing guide.

Core developers#

Core developers are community members that have demonstrated continued commitment to the project through ongoing contributions. They have shown they can be trusted to maintain scikit-image with care. Becoming a core developer allows contributors to merge approved pull requests, cast votes for and against merging a pull-request, and be involved in deciding major changes to the API, and thereby more easily carry on with their project related activities. Core developers appear as organization members on the scikit-image GitHub organization. Core developers are expected to review code contributions while adhering to the core developer guide.

New core developers can be nominated by any existing core developer. Discussion about new core developer nominations is one of the few activities that takes place on the project’s private management list. The decision to invite a new core developer must be made by “lazy consensus”, meaning unanimous agreement by all responding existing core developers. Invitation must take place at least one week after initial nomination, to allow existing members time to voice any objections.

Steering Council#

The Steering Council (SC) members are core developers who have additional responsibilities to ensure the smooth running of the project. SC members are expected to participate in strategic planning, approve changes to the governance model, and make decisions about funding granted to the project itself. (Funding to community members is theirs to pursue and manage.) The purpose of the SC is to ensure smooth progress from the big-picture perspective. Changes that impact the full project require analysis informed by long experience with both the project and the larger ecosystem. When the core developer community (including the SC members) fails to reach such a consensus in a reasonable timeframe, the SC is the entity that resolves the issue.

The steering council is fixed in size to five members. This may be expanded in the future. The initial steering council of scikit-image consists of Stéfan van der Walt, Juan Nunez-Iglesias, Emmanuelle Gouillart, Josh Warner, and Zachary Pincus. The SC membership is revisited every January. SC members who do not actively engage with the SC duties are expected to resign. New members are added by nomination by a core developer. Nominees should have demonstrated long-term, continued commitment to the project and its values. A nomination will result in discussion that cannot take more than a month and then admission to the SC by consensus.

The scikit-image steering council may be contacted at

Decision Making Process#

Decisions about the future of the project are made through discussion with all members of the community. All non-sensitive project management discussion takes place on the project developer forum and the issue tracker. Occasionally, sensitive discussion may occur on a private list.

Decisions should be made in accordance with the mission, vision and values of the scikit-image project.

Scikit-image uses a “consensus seeking” process for making decisions. The group tries to find a resolution that has no open objections among core developers. Core developers are expected to distinguish between fundamental objections to a proposal and minor perceived flaws that they can live with, and not hold up the decision-making process for the latter. If no option can be found without objections, the decision is escalated to the SC, which will itself use consensus seeking to come to a resolution. In the unlikely event that there is still a deadlock, the proposal will move forward if it has the support of a simple majority of the SC. Any vote must be backed by a scikit-image proposal (SKIP).

Decisions (in addition to adding core developers and SC membership as above) are made according to the following rules:

  • Minor documentation changes, such as typo fixes, or addition / correction of a sentence (but no change of the landing page or the “about” page), require approval by a core developer and no disagreement or requested changes by a core developer on the issue or pull request page (lazy consensus). Core developers are expected to give “reasonable time” to others to give their opinion on the pull request if they’re not confident others would agree.

  • Code changes and major documentation changes require agreement by two core developers and no disagreement or requested changes by a core developer on the issue or pull-request page (lazy consensus).

  • Changes to the API principles require a SKIP and follow the decision-making process outlined above.

  • Changes to this governance model or our mission, vision, and values require a SKIP and follow the decision-making process outlined above, unless there is unanimous agreement from core developers on the change.

If an objection is raised on a lazy consensus, the proposer can appeal to the community and core developers and the change can be approved or rejected by escalating to the SC, and if necessary, a SKIP (see below).

Improvement proposals (SKIPs)#

For all votes, a formal proposal must have been made public and discussed before the vote. After discussion has taken place, the key advocate of the proposal must create a consolidated document summarizing the discussion, called a SKIP, on which the core team votes. The lifetime of a SKIP detailed in SKIP 0 — Purpose and Process.

A list of all existing SKIPs is available here.