TL;DR — Key Takeaways
- The Linux Foundation has submitted its Open Model, Data, and Weights license, OpenMDW-1.1, to the Open Source Initiative for review and possible approval.
- OpenMDW is designed specifically for AI model distributions, covering weights, data, code, documentation and other model materials under a single permissive license.
- Unlike reciprocal licenses, OpenMDW generally allows commercial use and derivative models without requiring users to publish modifications or fine-tuned weights.
Open-source AI licenses have faced a difficult road to acceptance. The Linux Foundation hopes the Open Model, Data, and Weights license will find broad adoption.
People don’t like dealing with software licenses, but they’re essential. Dr. David Wheeler, Director of Open Source Supply Chain Security at the Linux Foundation, for instance, credits the GPLv2 for much of Linux’s success. When it comes to AI, though, there’s not a broadly accepted open-source license. That’s ironic since modern AI couldn’t exist without open-source software, but there it is.
That’s largely because defining open-source AI isn’t that simple. So, while the Open Source Initiative (OSI)‘s Open Source AI Definition (OSAID) 1.0 tried to lock down a license, many people aren’t happy with the OSAID. Other attempts, such as the European-based Open Weight Definition (OWD), haven’t made it past the draft stage. Now, the Linux Foundation has submitted its Open Model, Data, and Weights license to the OSI for review and potential approval as an AI open-source license.
The submission, made in mid-August by Mike Dolan, the Linux Foundation’s senior VP of legal and strategic programs, seeks OSI recognition for OpenMDW-1.1. This is a permissive licensing framework intended for AI model distributions rather than conventional software alone. The OSI has not yet decided.
OpenMDW is designed to cover a model release’s architecture, parameters or weights, data, supporting code, and documentation under one license. That scope addresses a recurring problem in AI licensing. That is, almost all open-source licenses such as Apache-2.0 and MIT were written for software and don’t expressly account for model weights, training or evaluation datasets, and the mixture of intellectual-property rights that comes with an AI release.
As currently written, the license grants recipients royalty-free rights to use, copy, modify and distribute covered “Model Materials.” Its terms are intended to extend across copyright, patent, database and trade-secret rights in the materials that a licensor provides under the agreement. It also permits commercial use and derivative works without field-of-use, geographic, or royalty restrictions.
OpenMDW is permissive rather than reciprocal. Users generally must preserve the license and relevant notices when redistributing covered materials, but they are not required to publish modifications, fine-tuned weights, or derivative models.
The Linux Foundation introduced the first OpenMDW release in 2025 as part of work around its Model Openness Framework. It released version 1.1 on May 28, 2026, with Amazon, Meta, IBM and Microsoft among the organizations involved in its development. Since then, NVIDIA has adopted OpenMDW for several model families, including Cosmos, Isaac GR00T, Ising, and Nemotron.
With all that corporate support, the OSI review and approval still matter because the OSI is broadly recognized as the defending group for all things open.
At the same time, AI companies often abuse the term “open “- I’m looking at you, Meta- by routinely applying it to AI systems whose released components aren’t really open at all. Some vendors make weights available but withhold training data, code, provenance information, or rights to modify and redistribute the materials. OSI approval wouldn’t settle every debate over what constitutes open-source AI, but it would give OpenMDW formal standing within the organization’s license-review process.
The OSI is still debating the license, but based on the ongoing discussions, I’m optimistic that after a few tweaks, the OSI will approve OpenMDW as an open-source license. This will take us one step closer to being able to say with confidence when an AI project is truly open source legally, rather than in our current situation, where the use of “open” about AI is often just a marketing term.