HoloViz Project Categorization & Policy Proposal Outline

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UPDATE: See this comment

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Purpose

To establish a clear, structured framework for categorizing HoloViz repositories and projects that:

1. Defines the relationship between different types of projects in the ecosystem
2. Sets expectations for maintenance, support, and quality standards
3. Creates paths for project progression and community involvement
4. Clarifies governance and decision-making processes across project categories

Proposed Project Categories

1. Core Projects (User-Facing Foundations, Highest Quality, HoloViz Team Led)

User-facing projects that are essential to the HoloViz ecosystem, domain-agnostic where possible, well-established, following a regular release cadence, and primarily maintained by the HoloViz team. Users should be able to depend on these packages for production use. Core projects require dedicated and comprehensive documentation and must maintain cross-compatibility with all other core projects in clearly defined ways. These projects come with a guarantee of maintenance by the HoloViz team. Core projects may include repositories for user-facing artifacts directly associated with other Core Projects, such as the HoloViz.org website.

Core status can be based on at least one of the following:

• Technical Maturity: Demonstrated stability, code quality, and robustness through multiple release cycles
• Community Adoption: Widespread usage and a significant user base
• Strategic Ecosystem Role: Serves as a primary entry point for specific user workflows or domains (e.g., Lumen for LLMs)
• Production Deployment: History of successful enterprise implementations

2. Extension Projects (User-Facing Enhancements, HoloViz Team Supported)

User-Facing projects that enhance the HoloViz ecosystem by adding functionality, integration, or demonstration capabilities beyond the scope of Core Projects. These projects come with a guarantee of maintenance by the HoloViz team. Extensions can be:

• Installable code libraries that complement Core Projects
• Collections of educational resources for specific HoloViz use cases
• Integration tools that connect HoloViz with other ecosystems

Extensions should maintain compatibility with their Core Project dependencies by:

• Setting minimum version pins on Core dependencies
• Testing against both minimum supported and latest Core versions
• Documenting version constraints when incompatibilities arise

Where applicable, Extensions follow the release cadence of their Core Project dependencies. They require appropriate documentation (comprehensive sites for libraries, detailed READMEs or sites for examples and resources).

Extensions can be led by community contributors but must involve at least one primary HoloViz team member for continuity and coordination. If an Extension loses its HoloViz team member, the Steering Committee has until either the next committee meeting or 3 months (whichever comes first) to appoint a replacement. Without a replacement, the Extension automatically transitions to Incubator status.

3. Developer Projects (Internal-Facing)

Projects that are not user-facing but are essential to the HoloViz ecosystem and primarily maintained by the HoloViz team. These packages are intended for use exclusively by HoloViz developers rather than end users. A Developer project may include meta-level repositories that are not intended to be user-facing, such as for project management.

4. Incubator Projects (Immature, No Guarantees)

Experimental or early-stage projects that require further development before being classified as Extensions or Core Projects. Incubator projects are expected to eventually progress to Extension, Core, or Archive status. These projects come with no guarantee of maintenance by the HoloViz team.

5. Community Projects (No Guarantees, HoloViz team may not be involved)

Projects created and maintained by the community that utilize HoloViz tools but operate on independent development cycles. Community projects benefit from visibility within a HoloViz-associated GitHub organization but are not expected to progress toward Core or Extension status. These projects come with no guarantee of maintenance by the HoloViz team.

6. Archive Projects (Use is not recommended)

Projects that are no longer actively maintained but are preserved for historical or reference purposes.

Project Category Standards

This table outlines the proposed standards and expectations for each project category (the first column is the criteria, the first row is the project types):

	Core	Extension	Developer	Incubator	Community	Archive
GitHub Org	holoviz	holoviz, panel-extensions, holoviz-topics	holoviz, holoviz-dev	holoviz-topics? holoviz-incubator(new)?	holoviz-community	holoviz-archive (new)?
Governance	Org and Project governance with Maintainers + Project Director	Org and Project governance with Maintainers + Project Director	Project-specific	Flexible	Independent	None
Testing	Standardized CI	Adapted CI	??	Encouraged	Independent	None
Documentation	Full docs site	Full docs site	Encouraged	At least a good README	Independent	None or with archived warning
Release Cycle	Regular, coordinated	Flexible, follows parent Core releases	Flexible	As needed	Independent	None
Support Level	High priority	Moderate, team-backed with community involvement	None	Best effort	Self-supported	None
Compatibility	Maximally compatible with other Core projects	Ensured with parent Core projects	As needed	Not guaranteed	Not guaranteed	Not guaranteed
Quality Standards	High	Moderate to High	Moderate	Varies	Independent	N/A
Designation Requires	Super majority of Steering Committee	Simple Majority of Steering Committee	Single maintainer of a Core project	Single maintainer of a Core project	Single maintainer of a Core project	Simple majority of Project's maintainer team or Steering Committee

Project Progression Paths

Incubator → Extension

• Requirements:
  • Demonstrated stable API
  • Sufficient test coverage
  • Basic documentation site
  • Active maintenance
  • Simple majority of Steering Committee

Incubator/Extension → Core

• Requirements:
  • Widespread adoption
  • Critical functionality
  • Comprehensive test suite
  • Complete documentation
  • Consistent maintenance
  • Super-majority approval by Steering Committee (>60% vote)

Any → Archive

• Triggers:
  • Inactivity for >X?? months
  • Superseded by another project
  • Request by maintainers
  • Simple majority of Project's maintainer team or Steering Committee

Extension → Incubator

• Triggers:
  • HoloViz maintainer support is lost and no replacement is appointed within 3 months.

Governance Implications

Steering Committee

• Approves promotion/demotion of projects for Core/Extension categories
• Resolves disputes between Project Teams

Project Teams

• Extension Project Teams require oversight from a Core maintainer
• Incubator Project Teams have flexible structure but need a designated lead

Implementation Plan

1. Document project categories in HoloViz governance
2. Categorize existing projects according to new framework
3. Establish necessary GitHub organizations (if not already existing) and transfer projects accordingly (Alternatively we could just add category labels to repos and leave them as is)
4. Update documentation to reflect new structure

Document Location

This resulting policy should peobably be added to the HoloViz governance documents in the main holoviz repository, potentially as a new file called PROJECT-CATEGORIES.md that would be referenced from the main CHARTER.md document.

HoloViz Repositories with Suggested Categories

Category	name	organization	description	url
Core	panel	holoviz	Panel: The powerful data exploration & web app framework for Python	https://github.com/holoviz/panel
Core	datashader	holoviz	Quickly and accurately render even the largest data.	https://github.com/holoviz/datashader
Core	holoviews	holoviz	With Holoviews, your data visualizes itself.	https://github.com/holoviz/holoviews
Core	hvplot	holoviz	A high-level plotting API for pandas, dask, xarray, and networkx built on HoloViews	https://github.com/holoviz/hvplot
Core	holoviz	holoviz	High-level tools to simplify visualization in Python.	https://github.com/holoviz/holoviz
Core	colorcet	holoviz	A set of useful perceptually uniform colormaps for plotting scientific data	https://github.com/holoviz/colorcet
Core	param	holoviz	Param: Make your Python code clearer and more reliable by declaring Parameters	https://github.com/holoviz/param
Core	lumen	holoviz	Illuminate your data.	https://github.com/holoviz/lumen
Core	geoviews	holoviz	Simple, concise geographical visualization in Python	https://github.com/holoviz/geoviews
Extension	examples	holoviz-topics	Visualization-focused examples using HoloViz for specific topics	https://github.com/holoviz-topics/examples
Extension	panel-chat-examples	holoviz-topics	Examples of Chat Bots using Panels chat features: Traditional, LLMs, AI Agents, LangChain, OpenAI etc	https://github.com/holoviz-topics/panel-chat-examples
Extension	spatialpandas	holoviz	Pandas extension arrays for spatial/geometric operations	https://github.com/holoviz/spatialpandas
Extension	panel-graphic-walker	panel-extensions	A project providing a Graphic Walker Pane for use with HoloViz Panel.	https://github.com/panel-extensions/panel-graphic-walker
Extension	holonote	holoviz	Tools to create, edit, and persist annotated regions for HoloViews	https://github.com/holoviz/holonote
Extension	jupyter-panel-proxy	holoviz	Jupyter Server Proxy for Panel	https://github.com/holoviz/jupyter-panel-proxy
Extension	panel-neuroglancer	panel-extensions	Volumetric data viewer in Jupyter notebooks with HoloViz Panel and Neuroglancer	https://github.com/panel-extensions/panel-neuroglancer
Extension	panel-full-calendar	panel-extensions	Extends HoloViz Panel with FullCalendar	https://github.com/panel-extensions/panel-full-calendar
Extension	panel-web-llm	panel-extensions	Extends HoloViz Panel with an interface that wraps a client-side LLM.	https://github.com/panel-extensions/panel-web-llm
Extension	panel-material-ui	panel-extensions	Panel extension to bring Material UI components to Panel	https://github.com/panel-extensions/panel-material-ui
Extension	panel-precision-slider	panel-extensions	A versatile slider with fine-tuned control, adjustable precision, and direct text input for exact values.	https://github.com/panel-extensions/panel-precision-slider
Extension	copier-template-panel-extension	panel-extensions	A copier template for creating Panel extensions, leveraging the pixi package manager to simplify setup and management.	https://github.com/panel-extensions/copier-template-panel-extension
Developer	pyviz_comms	holoviz	Bidirectional communication for the HoloViz ecosystem	https://github.com/holoviz/pyviz_comms
Developer	nbsite	holoviz-dev	Build a tested, sphinx-based website from notebooks	https://github.com/holoviz-dev/nbsite
Developer	nei	holoviz-dev	Notebook Editor Interface	https://github.com/holoviz-dev/nei
Developer	nbsmoke	holoviz-dev	Basic notebook checks. Do they run? Do they contain lint?	https://github.com/holoviz-dev/nbsmoke
Developer	pyctdev	holoviz-dev	Python packaging Common Tasks for Developers	https://github.com/holoviz-dev/pyctdev
Developer	blog	holoviz-dev	Source code for the HoloViz blog	https://github.com/holoviz-dev/blog
Developer	autover	holoviz-dev	Provides consistent and up-to-date version strings for Python packages.	https://github.com/holoviz-dev/autover
Developer	pyct	holoviz-dev	Python packaging Common Tasks	https://github.com/holoviz-dev/pyct
Developer	status-dashboard	holoviz-dev	Status Dashboard for HoloViz Project	https://github.com/holoviz-dev/status-dashboard
Developer	panelite	holoviz-dev	A JupyterLite deployment that supports Panel	https://github.com/holoviz-dev/panelite
Developer	.github	holoviz	Configuration files shared by the various repositories in the holoviz Github organization.	https://github.com/holoviz/.github
Developer	panel_dist	holoviz-dev	Serves the Panel Dist bundle on the pyviz-dev GitHub domain	https://github.com/holoviz-dev/panel_dist
Developer	panel-extensions	panel-extensions	A repository for organisation wide issues, feature requests, governance etc.	https://github.com/panel-extensions/panel-extensions
Developer	sphinx_holoviz_theme	holoviz-dev		https://github.com/holoviz-dev/sphinx_holoviz_theme
Developer	panel	holoviz-dev	Dev version of the Panel website	https://github.com/holoviz-dev/panel
Developer	param	holoviz-dev	Dev version of the param docs	https://github.com/holoviz-dev/param
Developer	examples	holoviz-dev	Dev website for https://examples.holoviz.org	https://github.com/holoviz-dev/examples
Developer	holoviz	holoviz-dev	Dev version of https://holoviz.org	https://github.com/holoviz-dev/holoviz
Developer	holoviz-dev.github.io	holoviz-dev	Index of all sites on holoviz-dev	https://github.com/holoviz-dev/holoviz-dev.github.io
Developer	hvplot	holoviz-dev	Repository to hold a development version of the hvplot docs	https://github.com/holoviz-dev/hvplot
Developer	geoviews	holoviz-dev		https://github.com/holoviz-dev/geoviews
Developer	colorcet	holoviz-dev	Dev site for colorcet	https://github.com/holoviz-dev/colorcet
Developer	datashader	holoviz-dev	Dev version of the datashader.org	https://github.com/holoviz-dev/datashader
Developer	contrib_colormaps	holoviz-dev		https://github.com/holoviz-dev/contrib_colormaps
Developer	lumen	holoviz-dev		https://github.com/holoviz-dev/lumen
Developer	holoviz_tasks	holoviz-dev	Shared GHA workflows and tasks used to maintain the HoloViz repositories	https://github.com/holoviz-dev/holoviz_tasks
Developer	nbsite-dev	holoviz-dev	Repository to hold a development version of nbsite	https://github.com/holoviz-dev/nbsite-dev
Developer	panelite-dev	holoviz-dev	JupyterLite distribution containing Panel	https://github.com/holoviz-dev/panelite-dev
Developer	blog-dev	holoviz-dev	Dev version of the blog	https://github.com/holoviz-dev/blog-dev
Developer	holonote	holoviz-dev	Repository to hold a development version of the holonote docs	https://github.com/holoviz-dev/holonote
Developer	holonote-jupyterlite	holoviz-dev	A JupyterLite deployment that supports HoloNote	https://github.com/holoviz-dev/holonote-jupyterlite
Developer	gh-discord-proxy	holoviz-dev		https://github.com/holoviz-dev/gh-discord-proxy
Developer	deep-dives	holoviz-dev	Artifacts and records for HoloViz Contributor Deep Dive sessions	https://github.com/holoviz-dev/deep-dives
Developer	panel-material-ui	holoviz-dev	Dev version of the Panel Material UI site	https://github.com/holoviz-dev/panel-material-ui
Developer	.github	panel-extensions		https://github.com/panel-extensions/.github
Developer	neuro	holoviz-topics	HoloViz+Bokeh for Neuroscience	https://github.com/holoviz-topics/neuro
Incubator	hvsampledata	holoviz	Shared datasets for the HoloViz projects	https://github.com/holoviz/hvsampledata
Incubator	imagen	holoviz-topics	ImaGen: Generic Python library for 0D, 1D and 2D pattern distributions	https://github.com/holoviz-topics/imagen
Incubator	holodoodler	holoviz-topics		https://github.com/holoviz-topics/holodoodler
Incubator	hv-anndata	holoviz-topics	Holoviz Anndata Interface	https://github.com/holoviz-topics/hv-anndata
Incubator	holoSeq	holoviz-topics	Jupyter visualisation notebooks supporting millions of points smoothly - must run in Jupyter/Bokeh/Panel serve for datashader	https://github.com/holoviz-topics/holoSeq
Incubator	cancer	holoviz-topics	Cancer research workflows in development	https://github.com/holoviz-topics/cancer
Incubator	lumen-cohort-builder	holoviz-topics	HoloViz's Lumen BigQuery app	https://github.com/holoviz-topics/lumen-cohort-builder
Community	HoloViz_KDD2022	holoviz-community	HoloViz tutorial for KDD 2022	https://github.com/holoviz-community/HoloViz_KDD2022
Community	contrib	holoviz-topics	Notebook, script and wiki contributions from PyViz users	https://github.com/holoviz-topics/contrib
Community	awesome-holoviz	holoviz-community	A collection of HoloViz resources!	https://github.com/holoviz-community/awesome-holoviz
Community	survey	holoviz-community	HoloViz user survey data	https://github.com/holoviz-community/survey
Community	needles_and_the_haystack_EuroPython23	holoviz-community	EuroPython 2023 talk	https://github.com/holoviz-community/needles_and_the_haystack_EuroPython23
Archive	EarthML	holoviz-topics	Tools for working with machine learning in earth science	https://github.com/holoviz-topics/EarthML
Archive	EarthML	holoviz-dev	Dev version of the earthml website	https://github.com/holoviz-dev/EarthML
Archive	EarthSim	holoviz-topics	Tools for working with and visualizing environmental simulations.	https://github.com/holoviz-topics/EarthSim