Open Weight Definition

A standard for AI model weight distribution that bridges open source and proprietary approaches

Overview

The Open Weight Definition (OWD) is a standardized framework that defines how [open weights] can be shared and used while balancing openness with practical constraints. Unlike traditional open source software that requires complete source code access, the OWD focuses specifically on making model weights freely available while allowing some elements (like training data) to remain proprietary.

The Definition

The OWD specifies ten critical requirements for AI models to be considered "open weight":

CriterionDescription
1. Free RedistributionNo restrictions on selling or giving away weights; no royalty fees required
2. Model WeightsMust include actual, unobfuscated weights with clear distribution channels; transformed versions must be clearly labeled
3. Derived WorksMust allow modifications and derived works under the same license terms
4. Author IntegrityMust permit distribution of modified weights while protecting original attribution
5. No Personal DiscriminationMust not discriminate against any person or group
6. No Usage DiscriminationMust not restrict use in any field (e.g., business, research)
7. License DistributionRights must apply to all recipients without additional licensing
8. License IndependenceRights must not depend on being part of a specific distribution
9. No Other RestrictionsMust not restrict other distributed components
10. Technology NeutralMust not be tied to specific technologies or interfaces

Key Requirements

Distribution and Access
  • Free sharing and redistribution of weights
  • Inclusion in larger model collections permitted
  • Easy access through well-publicized channels
  • Clear labeling of optimized or quantized versions
  • Reasonable reproduction costs, preferably free
Rights and Permissions
  • Modifications and derived works allowed
  • No discrimination against users or use cases
  • Technology-neutral implementation
  • Protection of original author attribution
  • No additional licensing requirements

Important Trade-offs

Benefits
  • Independent deployment of advanced AI technologies
  • No permission required for use
  • Clear labeling requirements
  • Responsible use guidelines
  • Accessibility for vendors not ready for full open source
For Developers
  • Clear distribution guidelines
  • Simplified licensing terms
  • Standardized sharing practices
  • Freedom to modify and adapt
  • Protected intellectual property
For the Community
  • Free access to model weights
  • Unrestricted commercial use
  • Enhanced collaboration
  • Educational opportunities
  • Accelerated AI innovation

Limitations

  • Training data may remain proprietary
  • Limited ability to study internal workings
  • Restricted capability to address bias at data level
  • Cannot fully modify model architecture
  • Fine-tuning may be the main modification option