Palimpsest-MPL (PMPL-1.0) is an open source license built on Mozilla Public License 2.0, with added provisions for:
- Ethical use guidelines (Exhibit A)
- Post-quantum cryptographic provenance (Exhibit B)
It's designed for the age of AI and quantum computing while remaining compatible with the established open source ecosystem.
A palimpsest is a manuscript where earlier writing has been erased and overwritten, but traces of the original remain visible. This metaphor captures how creative works accumulate layers of contribution and meaning over time. The license honors this layered nature of collaborative creation.
The base legal terms are identical to PMPL-1.0-or-later. PMPL-1.0 adds:
- Ethical use guidelines - Community norms around attribution, cultural sensitivity, and AI use
- Quantum-safe provenance - Optional cryptographic signatures using post-quantum algorithms
- Emotional lineage - Recognition of cultural and narrative meaning in creative works
The PMPL-1.0-or-later base is fully enforceable. The ethical use guidelines (Exhibit A) are primarily community norms enforced through reputation and community standards rather than litigation.
Yes. You can use PMPL-licensed code in:
- Personal projects
- Commercial products
- Open source projects
- Proprietary software (with conditions)
Yes. Commercial use is permitted. The ethical use exhibit asks commercial users to:
- Acknowledge the ethical guidelines
- Act in good faith
- Support communities whose work enables their products
No. PMPL-1.0 has file-level copyleft like PMPL-1.0-or-later:
- Modified PMPL files must remain under PMPL
- Your own files can be under any license
- You can combine PMPL code with proprietary code in separate files
Yes, with expectations:
- Document the training use
- Don't claim AI outputs have the creative authority of the training data
- Preserve attribution through your pipeline
- Consider opt-out mechanisms
- Add
PALIMPSEST-MPL-1.0.txtas your LICENSE file - Add SPDX headers to source files:
SPDX-License-Identifier: PMPL-1.0 - Include copyright notices in headers
- Optionally add provenance signatures
Quantum-safe signatures are optional but recommended. They:
- Prove authorship cryptographically
- Create an audit trail
- Remain secure against quantum computers
- Help with long-term attribution
If relicensing an existing project:
- Get explicit consent from all contributors
- Document the license change
- Keep attribution for all contributions
- Consider a CLA for ongoing contributions
PMPL-1.0 is compatible with GPL 2.0+ and LGPL 2.1+ as secondary licenses (per PMPL-1.0-or-later Section 3.3). This means:
- GPL/LGPL code can be combined with PMPL code
- The combined work follows GPL/LGPL terms
- The original PMPL files remain available under PMPL
Yes. PMPL-1.0 and Apache 2.0 are compatible:
- Can be combined in the same project
- Apache 2.0 code remains under Apache 2.0
- PMPL code remains under PMPL
Yes. MIT and BSD code can be:
- Combined with PMPL code
- Kept under their original licenses
- Used in the same project
Emotional lineage refers to the cultural, narrative, and symbolic meaning embedded in creative works. This includes:
- Protest traditions and social movements
- Cultural heritage and community stories
- Trauma narratives and lived experiences
- Spiritual and religious content
The license asks users to respect this context, not just the code.
The guidelines in Exhibit A are primarily community norms:
- They set expectations for ethical behavior
- They're enforced through community reputation
- Serious violations could potentially be actionable under related laws
- The Stewardship Council may issue public statements about violations
The guidelines represent community consensus. If you disagree:
- You can still use the software (guidelines are voluntary)
- Submit feedback via the project repository
- Propose alternative approaches through the governance process
- Fork the project under PMPL-1.0-or-later if guidelines conflict with your needs
No. The cryptographic requirements are implemented in tools:
- Use
pmpl-signto sign files - Use
pmpl-verifyto verify signatures - The tools handle the cryptography
Current estimates suggest:
- 2030-2040 for cryptographically relevant quantum computers
- Some recommend "harvest now, decrypt later" protection today
- PMPL signatures are designed to remain valid for 50+ years
The Stewardship Council maintains the approved algorithm list:
- New algorithms can be added as needed
- Deprecation follows a 2-year notice period
- Signature format supports algorithm agility
The Palimpsest Stewardship Council:
- 3 Creator Representatives
- 2 Legal Experts
- 1 Technologist
- 1 Cultural Heritage Advocate
Ways to contribute:
- Submit issues and feedback via GitHub
- Join community discussions
- Propose amendments through the governance process
- Apply for Council membership when positions open
Future versions may be published:
- You can always use software under the version it was released under
- Or any later version (your choice)
- Major changes require Council supermajority and community review
- GitHub Issues: Technical questions and bug reports
- GitHub Discussions: Broader topics and community conversation
- Email: Contact the Council for sensitive matters
- Repository: https://github.com/hyperpolymath/palimpsest-license
- License:
legal/PALIMPSEST-MPL-1.0.txt - Exhibits:
legal/exhibits/
- Try to resolve directly with the violator first
- Contact the Stewardship Council for guidance
- Seek legal counsel for serious violations
- Document everything for potential enforcement