A field guide to AI positions

Open weights & open-source AI

Access & release.

Publication dates and source age

Sources counted: 1

Publication dates are unavailable.

Assessed at this edition's evidence cutoff: 2026-09-15. 18-month boundary: 2025-03-15.

Some publication dates are unknown; the newest dated source may not be the newest source overall.

Publication age does not tell us whether a claim is still valid. Reading an old source again does not make its publication date newer. An update date does not establish that the passage we used was updated.

Open in the glossary Reading notes · Structured record

Prepared with AI assistance. Not independently fact-checked. Original sources and qualifications are below.

In plain language

Releasing model weights gives access to its learned settings; fuller openness also concerns code, training information and usage rights. [1]

Reference this explanation or suggest a correction

Explanation based on the linked sources. Claim ID: claim-term-open-weights-1a5192ba3d7825ca26b24a72. Edition 0.20.0.

Link to this explanation · Suggest a correction · How corrections work

Limits & distinctions

A download alone does not establish that OSI's definition is met. Check the release terms and accompanying materials. [1]

Reference this explanation or suggest a correction

Explanation based on the linked sources. Claim ID: claim-term-open-weights-09422ce4d5c74cb753a9bb98. Edition 0.20.0.

Link to this explanation · Suggest a correction · How corrections work

A fuller explanation

A weights release makes learned parameters available. Under the Open Source Initiative's AI definition, openness also requires training and inference code, sufficient training-data information, and rights to use, study, modify and share the system. [1]

Reference this explanation or suggest a correction

Explanation based on the linked sources. Claim ID: claim-term-open-weights-1e4c26398ee834b2e16dc7b8. Edition 0.20.0.

Link to this explanation · Suggest a correction · How corrections work

How it relates to the map

When a model is called 'open', check exactly which materials and permissions are available. [1]

Reference this explanation or suggest a correction

Editorial interpretation or qualification. Claim ID: claim-term-open-weights-25f52a21ad9f2e54a62ed1b2. Edition 0.20.0.

Link to this explanation · Suggest a correction · How corrections work

Share this page

https://theaiatlas.org/ideas/open-weights/

Download a share image · Vector image

Image previews are summaries. Keep the page link so readers can check the evidence.

Sources and what we read

  1. 1. The Open Source AI Definition – 1.0

    Open Source Initiative · First-hand source · Published date unavailable · Material last read 2026-09-15

    Publication dates and source age

    Sources counted: 1

    Publication dates are unavailable.

    Assessed at this edition's evidence cutoff: 2026-09-15. 18-month boundary: 2025-03-15.

    Some publication dates are unknown; the newest dated source may not be the newest source overall.

    Publication age does not tell us whether a claim is still valid. Reading an old source again does not make its publication date newer. An update date does not establish that the passage we used was updated.

    Read scope is described in the source note.

    No archive check recorded.

    Browser-tool fetch returned 403; fetched and read the original publisher HTML directly. Read the four freedoms and requirements for data information, code and parameters. This is OSI's definition, not a claim that every publisher uses the label identically. Live page publication date unspecified.

    Source ID: osi-ai-definition

Edition and machine-readable evidence

Content version 0.20.0. Evidence cutoff 2026-09-15; this does not mean every source was read on that day.

Pinned complete dataset · Complete evidence page · Agent consumption guide