Open Source Initiative

The Open Source Initiative (OSI) is a United States-based nonprofit organization established in 1998 to promote and protect the open-source software movement. Its principal role is stewardship of the Open Source Definition (OSD), a set of ten criteria used to determine whether a software license qualifies as open source. The organization also maintains a public list of licenses that it has approved as conforming to the definition and participates in public discussions about software freedom, licensing, technology policy, and the governance of shared digital infrastructure. The organization emerged during a period when developers and technology companies were seeking language that could explain the practical and collaborative advantages of releasing software source code. The immediate background included Netscape Communications Corporation's decision to publish the source code for Netscape Communicator. In February 1998, Bruce Perens and Eric S. Raymond helped establish the OSI, alongside contributors to the broader campaign to popularize the term "open source," including Christine Peterson, Jon "maddog" Hall, and Larry Augustin. The OSD drew substantially on the Debian Free Software Guidelines, while presenting the concept in terminology intended to be more accessible to businesses and commercial software users. OSI's most visible service is license evaluation. A license seeking approval is generally submitted with an explanation of its purpose, comparison with existing licenses, and legal analysis. The proposal is discussed publicly for a defined period before the board considers whether it satisfies the OSD. Approved licenses may be permissive, allowing broad reuse and relicensing, or copyleft, requiring certain derivative or redistributed works to remain under compatible free or open terms. Frequently used licenses recognized by OSI include the Apache License 2.0, MIT License, BSD licenses, the GNU GPL and LGPL families, Mozilla Public License 2.0, Eclipse Public License 2.0, and Common Development and Distribution License. For much of its history, OSI operated through a relatively closed organizational model centered on its board and license stewardship. During the 2010s it began moving toward broader membership and participation structures, including affiliate membership for nonprofit, academic, and industry associations, individual membership, and corporate sponsorship. This transition was intended to broaden representation, strengthen the organization's finances, and support work beyond the maintenance of the OSD. OSI has also become involved in questions surrounding artificial intelligence and the meaning of open source outside conventional software. It began developing the Open Source AI Definition in 2022 with researchers, developers, and industry participants. Version 1.0 was released in October 2024, although the definition attracted criticism from some employees and participants connected with AI companies. The initiative illustrates the organization's continuing effort to apply open-source principles to new technical domains while preserving requirements concerning access, modification, and reuse. The organization is a California public-benefit nonprofit corporation with United States 501(c)(3) tax-exempt status. It is overseen by a board of directors and professionally managed by an executive director and staff. Its governance has periodically drawn scrutiny, including a 2021 board-election security incident and criticism of the 2025 election process. In January 2026, OSI announced that its board had voted to redesign the process for selecting board members and suspend the 2026 board elections while that redesign was undertaken. OSI remains active internationally as a standards-oriented advocate, license certifier, and institutional representative for open-source software.

The Open Source Initiative was created in 1998 during an effort to establish a business-friendly and technically precise public vocabulary for software developed and shared through source-code collaboration. The immediate context was Netscape Communications Corporation's decision to release the source code for Netscape Communicator. Participants in the wider naming and advocacy effort included Christine Peterson, Jon "maddog" Hall, Larry Augustin, Eric S. Raymond, and Bruce Perens. Perens and Raymond founded the OSI in February 1998, and a board of directors was added later that year. The organization adopted the Open Source Definition, drawing heavily on the Debian Free Software Guidelines. The definition was designed to distinguish open source from the narrower idea of merely publishing source code. Among its requirements are access to source code, permission to modify and redistribute software, nondiscrimination against people or fields of endeavor, and permission for commercial use. The definition supports both permissive licenses and copyleft licenses. OSI and the Free Software Foundation therefore recognize many of the same licenses and share important practical objectives, although their terminology and institutional histories differ. An early attempt to secure a trademark over the phrase "open source" was unsuccessful, leaving the term broadly available rather than controlled by OSI. For most of its existence, OSI concentrated on maintaining the definition, reviewing license proposals, and certifying licenses as compliant. The normal approval process involves a formal submission, explanatory and comparative material, legal analysis, public discussion for at least 30 days, and a board decision. This process has helped create a recognizable reference point for projects, companies, governments, and legal teams, but it has also generated debate over license proliferation, the boundaries of open-source licensing, and the transparency of decision-making. During the 2010s, OSI began moving away from its earlier closed organizational model. Under the leadership of director and then board president Simon Phipps, it developed affiliate membership for recognized nonprofit, charitable, industry, and academic organizations, followed by individual membership and corporate sponsorship. The change aimed to improve financial support, widen participation, and allow OSI to undertake broader advocacy and educational work. Operational leadership changed several times in the following decade. Patrick Masson became general manager in 2013. Deb Nicholson served as interim general manager from August 2020 to September 2021. In November 2020, the board announced a search for an executive director, culminating in Stefano Maffulli's appointment in September 2021. At the same time, the board discontinued the title of president in favor of chair. Maffulli stepped down in September 2025, with Deborah Bryant serving as interim executive director. Governance controversies have also formed part of OSI's recent history. Bruce Perens resigned in January 2020 amid disagreement about the impending approval of the Cryptographic Autonomy License. He argued that the license was inconsistent with his understanding of software freedom and later criticized license proliferation. In the March 2021 board election, OSI discovered that a security vulnerability had allowed at least one voter to submit multiple ballots. The results were invalidated and the election was held again. The 2025 board election generated further criticism concerning the communication of available seats, a candidate agreement introduced after voting, the exclusion of three candidates, and requests for fuller publication of vote totals. OSI maintained that the election was valid. In January 2026, the board announced a redesign of its member-selection process and suspension of the 2026 board elections. OSI expanded its subject matter in the 2020s by addressing artificial intelligence. Work on the Open Source AI Definition began in 2022 with participation from researchers, developers, and industry representatives. Version 1.0 was released in October 2024 and sought to apply open-source principles to AI systems and their essential components. The document was controversial, including criticism from some AI company employees, but it demonstrated OSI's attempt to extend its standards role beyond conventional software licensing. Today, OSI remains a California public-benefit nonprofit and 501(c)(3) organization focused on licensing standards, public education, community participation, and policy advocacy for open-source software and adjacent technologies.

• 2026

  Board-election process suspended for redesign

  [1]Open Source Initiativeen.wikipedia.org

  OSI announced that its board had voted to redesign the board-member selection process and suspend the 2026 elections.

• 2025

  Executive leadership changes and election criticism

  [1]Open Source Initiativeen.wikipedia.org

  Stefano Maffulli stepped down, Deborah Bryant became interim executive director, and the board election attracted criticism from members and other open-source participants.

• 2024

  Open Source AI Definition 1.0 released

  [1]Open Source Initiativeen.wikipedia.org

  OSI published version 1.0 of its Open Source AI Definition in October.

• 2022

  Open Source AI Definition work begins

  [1]Open Source Initiativeen.wikipedia.org

  OSI began a multi-stakeholder effort to define open-source principles for artificial intelligence.

• 2021

  Board election rerun

  [1]Open Source Initiativeen.wikipedia.org

  A voting vulnerability led OSI to discard the initial election result and conduct the election again.

• 2020

  Bruce Perens resigns

  [1]Open Source Initiativeen.wikipedia.org

  Co-founder Bruce Perens resigned after objecting to the expected approval of the Cryptographic Autonomy License.

• 2013

  Patrick Masson appointed general manager

  [1]Open Source Initiativeen.wikipedia.org

  Patrick Masson took responsibility for the organization's general management.

• 2012

  Membership transition begins

  [1]Open Source Initiativeen.wikipedia.org

  OSI began shifting toward membership-based governance and launched an affiliate membership program.

• 1998

  Open Source Initiative founded

  [1]Open Source Initiativeen.wikipedia.org

  Bruce Perens and Eric S. Raymond founded OSI in February during the campaign that popularized the term open source.

• 1998

  Board of directors added

  [1]Open Source Initiativeen.wikipedia.org

  OSI added a board of directors in August, formalizing governance for the new stewardship organization.

A standards-setting, licensing, and advocacy institution for the open-source software ecosystem.

• Standard · 1998

  Open Source Definition

  The Open Source Definition is OSI's central standard for determining whether software licensing terms qualify as open source. It contains ten criteria covering source-code availability, modification, redistribution, commercial use, and nondiscrimination. The definition accommodates both permissive and copyleft licensing models and serves as the basis for OSI's license-review work.

• License certification · 1998

  OSI Approved Licenses

  OSI maintains a catalog of licenses judged compliant with the Open Source Definition. The catalog includes widely used permissive licenses such as MIT, Apache 2.0, and BSD licenses, as well as copyleft and source-available-on-distribution licenses such as the GPL, LGPL, Mozilla Public License, Eclipse Public License, and CDDL families.

• Artificial intelligence standard · 2024

  Open Source AI Definition

  The Open Source AI Definition extends OSI's standards work into artificial intelligence. Developed through a process involving researchers, developers, and industry representatives, version 1.0 was released in October 2024. It addresses how openness should be evaluated for AI systems and their essential components, while remaining the subject of public debate.

• Community program · 2012

  Membership and affiliate programs

  OSI's membership initiatives provide participation routes for individuals, academic organizations, nonprofits, industry associations, and corporate supporters. They were introduced as part of the organization's move toward broader membership-based governance and expanded operational support.

• 2025

  Criticism of board-election administration

  Members and other open-source community participants criticized errors in communicating the number of seats, the timing of candidate requirements, the exclusion of three candidates, and OSI's refusal to invalidate and repeat the election or publish complete tallies.

  Source

• 2021

  Board-election voting vulnerability

  OSI found that at least one voter had exploited a security vulnerability to submit multiple votes. The organization discarded the results and reran the election.

  Source

• 2020

  Bruce Perens resignation and license-proliferation dispute

  Co-founder Bruce Perens resigned while objecting to the anticipated approval of the Cryptographic Autonomy License. He argued that the license did not adequately respect software freedom and later raised broader concerns about proliferation of overlapping licenses.

  Source

Read more

• 2022Open Source AI Definition initiative

  Global

  OSI convened contributors from research, software development, and industry to examine how open-source requirements could apply to artificial intelligence.

  Outcome. Version 1.0 of the definition was released in October 2024, alongside continuing public debate.

  Source
• 2012Membership expansion

  Global

  OSI introduced affiliate and later individual membership structures to broaden participation and increase support for advocacy, education, and standards work.

  Outcome. The organization moved toward a more participatory membership model.

  Source
• 1998Open source naming and advocacy campaign

  Global

  OSI coalesced with a broader campaign to promote the term open source as a practical description of collaborative software development and a concept suitable for commercial adoption.

  Outcome. The term became widely used, while OSI became a principal steward of its licensing definition.

  Source

• 2026

  Suspend board elections during governance redesignStrategy

  Background

  The decision followed criticism of the 2025 board-election process and broader discussion of OSI's member-selection procedures.

  Action taken

  The board voted to redesign the process for selecting board members and suspend the 2026 elections during that work.

  Aftermath

  The change temporarily paused the normal election cycle while OSI reconsidered its governance process.

  Source

• 2024

  Release Open Source AI Definition 1.0Product launch

  Background

  OSI's AI working process began in 2022 and sought to adapt open-source principles to AI systems.

  Action taken

  OSI published version 1.0 of the Open Source AI Definition in October 2024.

  Aftermath

  The definition became a new reference point in debates over open AI terminology and policy.

  Source

• 2022

  Extend standards work to artificial intelligenceStrategy

  Background

  The expansion of AI created demand for clearer terminology concerning openness, model components, data, and rights to use or modify systems.

  Action taken

  OSI began a multi-stakeholder process to develop the Open Source AI Definition.

  Aftermath

  The process produced version 1.0 in 2024 but also generated criticism from some AI-industry participants.

  Source

• 2021

  Rerun the board election after a voting incidentOther

  Background

  A security vulnerability was used to submit multiple votes during the March board election.

  Action taken

  OSI discarded the initial results and conducted the election again.

  Aftermath

  The incident intensified attention on OSI's electoral controls and governance transparency.

  Source

• 2012

  Adopt a membership-based governance directionStrategy

  Background

  OSI sought broader participation and additional support for work beyond license certification.

  Action taken

  It created affiliate membership and subsequently expanded to individual membership and corporate sponsorship.

  Aftermath

  The organization became more institutionally open and participatory than its earlier closed model.

  Source

1. 1Open Source Initiativeen.wikipedia.org
2. 2Open Source Initiative official websiteopensource.org