What Is the Open Source Initiative?

The History of the OSI

The Open Source Initiative was founded by Eric S. Raymond and Bruce Perens in February 1998, during a period of intense debate about how to promote free and open source software to businesses and the general public. The free software movement, led by Richard Stallman and the Free Software Foundation (FSF), had been advocating for software freedom since the 1980s, but its emphasis on ethical principles and its opposition to proprietary software made many business leaders uncomfortable.

Raymond and Perens believed that reframing the conversation around practical benefits, emphasizing the superior development methodology, code quality, and cost savings of openly developed software, would be more effective at driving corporate adoption. They coined the term "open source" as a marketing-friendly alternative to "free software" (which was often misunderstood as meaning "free of charge" rather than "free as in freedom") and created the OSI to promote this new framing.

The Open Source Definition itself was adapted from the Debian Free Software Guidelines (DFSG), which Bruce Perens had written for the Debian project. The DFSG established the criteria for what software could be included in Debian's main repository, and these criteria, with modifications, became the ten provisions of the Open Source Definition. This lineage connects the OSI directly to one of the oldest and most principled open source communities in existence.

The Open Source Definition

The Open Source Definition (OSD) is a ten-point document that specifies the conditions a software license must meet to be classified as open source. Understanding these criteria is essential for anyone evaluating whether a license truly qualifies as open source or whether it uses the term loosely.

The first and most fundamental requirement is free redistribution: the license cannot restrict anyone from selling or giving away the software as part of a larger distribution. The second requirement is source code: the program must include source code, or the source code must be available by clearly publicized means at no more than a reasonable reproduction cost. The third is derived works: the license must allow modifications and derived works, and must allow them to be distributed under the same terms as the original license.

Other provisions address integrity of the author's source code (allowing patch files as an alternative to direct modification), no discrimination against persons, groups, or fields of endeavor, distribution of license rights without requiring additional agreements, the license not being specific to a product, the license not restricting other software distributed alongside it, and technology neutrality. Together, these ten provisions define a clear boundary between software that is genuinely open source and software that merely makes its source code visible without granting meaningful freedoms.

The OSI's Role Today

Beyond license stewardship, the OSI plays several roles in the broader open source ecosystem. The organization advocates for open source adoption in government, working with policymakers on procurement standards, digital sovereignty initiatives, and open data policies. The OSI has been particularly active in the European Union, where digital policy debates frequently intersect with open source interests.

The OSI also serves as a community convener and educator. It organizes the annual State of Open Source report, maintains a directory of OSI-approved licenses with explanations of their terms, and runs outreach programs aimed at helping businesses, governments, and individuals understand the practical and legal implications of open source software. The organization's blog and social media presence provide commentary on emerging issues in the open source world, from AI model licensing to software supply chain security.

In recent years, the OSI has faced challenges in maintaining its relevance as the open source ecosystem has grown and diversified. The rise of "source available" licenses, which make source code visible but do not meet the OSD's requirements for modification and redistribution, has created ongoing debates about the boundaries of open source. Companies like HashiCorp, Elastic, and MongoDB have moved from OSI-approved licenses to custom licenses that restrict certain commercial uses, prompting the OSI to clarify that these licenses, while legitimate business choices, do not qualify as open source.

The OSI and AI

One of the most significant recent challenges for the OSI has been defining what "open source" means in the context of artificial intelligence. Traditional open source definitions were written for software, where the source code is the complete description of the program. AI models are different: their behavior is determined not just by code but by training data, model weights, and training methodologies that may not be fully reproducible even when shared.

The OSI launched a process in 2023 to develop an Open Source AI Definition (OSAID), engaging with researchers, companies, and community members to determine what freedoms an AI system must provide to qualify as "open source." The resulting definition, published in 2024, addresses the unique challenges of AI transparency, including requirements around training data documentation, model weights availability, and the ability to study, modify, and share AI systems. This work has become increasingly important as AI systems proliferate and governments consider regulations that may distinguish between open and closed AI models.

OSI Governance and Membership

The OSI is governed by a board of directors, some of whom are elected by the organization's individual and affiliate members. Individual membership is open to anyone who supports the OSI's mission, and affiliate membership is available to organizations that want to support open source advocacy. The board sets organizational strategy, oversees the license review process, and represents the OSI in policy discussions.

The organization's staff is small, and much of its work is done by volunteers and committee members. The License Review Committee, the Policy and Advocacy Committee, and various working groups handle the operational work of license evaluation, policy analysis, and community engagement. This volunteer-driven model keeps the OSI's operating costs low but also means that the organization's capacity is limited by the availability of its volunteers.

Why the OSI Matters

The OSI's primary value is as a standard-setter. In a world where "open source" is used loosely by companies, marketers, and policymakers, the OSI provides a rigorous, community-developed definition that separates genuine open source from imitations. This definitional clarity protects users and contributors: when you see an OSI-approved license, you know that the license has been evaluated against a published standard and that it grants you specific, meaningful freedoms.

The OSI also serves as institutional memory for the open source movement. Its archives of license discussions, policy positions, and community debates document three decades of thinking about how to make collaborative software development work at scale. For anyone navigating the complex landscape of open source licensing, governance, or policy, the OSI is an essential reference point.