Glossary
OSI
The nonprofit that maintains the canonical Open Source Definition for software since 1998, and the OSAID definition for AI as of 2024.
The standards body for what counts as “open source.” Founded in 1998, the OSI maintains the Open Source Definition (a ten-point checklist descended from the Debian Free Software Guidelines) and approves licenses that meet it. Vendors that want to claim a license is “OSI- approved open source” submit it for review against the definition.
OSI’s relevance for AI is the OSAIDgovernanceThe OSI's October 2024 definition of "open source AI," requiring not just weights but enough information about data, code, and architecture for third parties to reproduce the system. Open full entry work (OSAIDgovernanceThe OSI's October 2024 definition of "open source AI," requiring not just weights but enough information about data, code, and architecture for third parties to reproduce the system. Open full entry , released October 2024). It extends the principles of the Open Source Definition to AI systems: weights are not enough; you also need sufficient information about training data, code, and architecture so a third party can study, modify, and reproduce the system.
The definition is contested. Major labs use “open source” as a marketing term for weight releases that do not meet OSAID criteria; the OSI has been clear that those releases are not OSAID-compliant even if the term is widespread. Whether OSI’s definition or the broader market usage prevails is one of the live governance fights through 2026.