Open Source Initiative

A non-profit built around a shared definition

The Open Source Initiative (OSI) is a non-profit corporation with global scope. It was founded in 1998 to educate people about the benefits of open source and to advocate for them, and to build bridges among the different constituencies that make up the open source community.^[1] It is based in Raleigh, North Carolina.^[1] Carlo Piana is the chair of its board, and Stefano Maffulli is its executive director.^[1]

The word "open source" describes software whose source code can be read, modified and redistributed under a licence that allows it. Because that promise depends entirely on the wording of a licence, the community needs an agreed reference for which licences qualify and what the term obliges people to do. Providing that reference is the job OSI has taken on.

Steward of the definitions

OSI is the steward of the Open Source Definition, the document that sets out what the label means, and which sets the foundation for the global open source ecosystem.^[1] Since 2024 it has stewarded a second document, the Open Source AI Definition (OSAID).^[1] Both are reference texts rather than laws: they describe conditions, and the community, projects and companies decide whether to follow them.

The Open Source AI Definition

OSI released version 1.0 of the Open Source AI Definition on 28 October 2024 at the All Things Open conference.^[1] Maffulli said the result was aligned with the expectations set at the start of a two-year process — a process that included differing opinions and uncharted technical frontiers.^[1] The text of OSAID v.1.0, together with a partial list of the global stakeholders who endorse the definition, is published at opensource.org/ai.^[1]

Writing a definition for AI is harder than for software because a model is delivered differently. A user may receive model weights and information about training data alongside code, not just source files, while the Open Source Definition was written with software in mind. A new text therefore has to say what a recipient of a model must be given for the label "open source" to be fair.

Funding and the policy context

According to TechCrunch, companies funding OSI's work include Meta, Amazon, Google, Microsoft, Cisco, Intel and Salesforce, and OSI recently secured a grant from the Sloan Foundation to lessen its reliance on tech industry backers.^[2] Maffulli told TechCrunch that regulators, including the European Commission, already watch the space and give special recognition to open source, and that OSI did explicit outreach to a diverse set of stakeholders.^[2]

What the definition can and cannot do

OSI has no enforcement mechanisms to speak of and cannot pressure developers to follow the OSAID. What it intends to do is flag models that are described as open source but fall short of the definition.^[2] In a field where the label carries commercial weight as well as practical meaning — users want to know whether they can inspect, change and reuse a system — a public flag is the main instrument available.

Where it sits

OSI's influence comes from being the place where the vocabulary is settled. A definition written by a non-profit with no enforcement power only works if developers, companies and regulators treat it as the reference point, which is why the endorsement list and the outreach to stakeholders matter as much as the text itself.