The Project#

The ArviZ Project (The Project) is an open source software project affiliated with the 501c3 NumFOCUS Foundation. The goal of The Project is to develop open source software and deploy open and public websites and services for reproducible, exploratory and interactive computing.

The Software developed by The Project is released under OSI approved open source licenses, developed openly and hosted in public GitHub repositories under the arviz-devs GitHub organization. Examples of Project Software include the code of the two ArviZ libraries and their Documentation, etc. The Services run by the Project consist of public websites and web-services that are hosted at

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. 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, Slack, and Gitter chat rooms. The foundation of Project participation is openness and transparency.

There have been many Contributors to the Project, whose contributions are listed in the logs of any of the repositories under the ArviZ-devs organization.

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 501c3 NumFOCUS Foundation (, NumFOCUS is the only legal entity that has a formal relationship with the project.


The foundations of Project governance are:

  • Openness & Transparency

  • Active Contribution

  • Institutional Neutrality

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

Historical note#

Initially, project leadership was unstructured but primarily driven by a subset of Core Contributors whose active and consistent contributions have been recognized by their receiving “commit rights” to the Project GitHub repositories. In general all Project decisions were made through consensus among the Core Contributors with input from the Community.

While this approach served us well, as the Project grew and faced more legal and financial decisions and interacted with other institutions, we saw a need for a more formal governance model. We also wanted to prevent falling prey to the tyranny of structurelessness. Since 2020, The Project leadership consists of a Random Variables Council. We view this governance model as the formalization of what we are already doing, rather than a change in direction.