Welcome to the glossary for the Open Source Program Offices (OSPOs) Book. As you may know, the world of open source is vast and complex, with many different terms and concepts that can be difficult to navigate. Our aim with this glossary is not to provide a definitive or general definition of these terms, but to clarify what we mean specifically under the context of this book.

We believe that it is important to be concise and clear in our definitions, and to reference existing descriptions and resources whenever possible. This will help us avoid creating a glossary that is overly complex or difficult to understand, and will ensure that our readers have access to the best information and resources available.

The content below contains links to the original authors, foundations, NGOs, or academic institutions that created and/or maintain these definitions.

  • Free Content: Also known as libre content, libre information, or free information, is any kind of functional work, work of art, or other creative content that meets the definition of a free cultural work. Learn more about Free Content at

  • Free Cultural Works: The Definition of Free Cultural Works evaluates and recommends compatible free content licenses. Thus one that has no significant legal restriction on people’s freedom to:

    • Use the content and benefit from using it,
    • Study the content and apply what is learned,
    • Make and distribute copies of the content,
    • Change and improve the content and distribute these derivative works

Learn more about Free Cultural Works at

  • Free Software: Free Software refers to freedom, not price. It guarantees its users the essential four freedoms (Use, Study, Share, Improve) The absence of at least one of these freedoms means an application is proprietary, so non‐Free Software. Learn more:

  • InnerSource: is the use of open source software development best practices and the establishment of an open source-like culture within organizations for the development of its non-open-source and/or proprietary software.

  • InnerSource Principles: InnerSource Principles are a set of guidelines that provide a framework for organizations to tap into the collective knowledge and expertise of their employees, and to create a culture of collaboration and innovation. Learn more about InnerSource principles:

  • Knowledge Sharing: Knowledge sharing refers to the exchange of information and expertise between individuals, teams, and organizations. Knowledge sharing is often a key component of open source and innerSource development practices. Learn more about knowledge sharing:

  • Open (Data and Content): The Open Definition sets out principles that define openness in relation to data and content. Open means anyone can freely access, use, modify, and share for any purpose (subject, at most, to requirements that preserve provenance and openness). Open data and content can be freely used, modified, and shared by anyone for any purpose. Learn more about open definition at

  • Open Innovation: Open innovation assumes that useful knowledge is widespread, so that one needs to innovate by developing effective mechanisms to access this useful knowledge, and to share useful knowledge with others. Open Innovation is based on the fundamental idea that useful knowledge is now widespread throughout society. No one organization has a monopoly on great ideas, and every organization, no matter how effective internally, needs to engage deeply and extensively with external knowledge networks and communities. An organization that practices open innovation will utilize external ideas and technologies as a common practice in their own business and will allow unused internal ideas and technologies to go to the outside for others to use in their respective businesses. Learn more about open innovation:

  • Open Source: Open source refers to a type of software that allows users to freely use, modify, and distribute the source code of a program that must comply with certain distribution criteria. Learn more about open source:

  • Open Source Culture: Open source culture refers to a set of values and practices that promote collaboration, transparency, and community-driven development. It is often associated with the open source software movement, but can be applied to other areas as well, such as open science, open hardware, and open education. For this book, we will base on the four opens philosophy, created by the OpenStack community. Learn more about:

  • Open Source Software Ecosystems: To understand what an open source software ecosystem is, researchers have first explored the definition of software ecosystems. Some widely accepted definitions of software ecosystems are:

    • A set of actors functioning as a unit and interacting with a shared market for software and services, together with the relationships among them
    • A collection of software projects which are developed and evolve together in the same environment.
    • A set of software solutions that enable, support and automate the activities and transactions by the actors in the associated social or business ecosystem and the organizations that provide these solutions

Regarding open source software ecosystems, there are only a few specific definitions provided by authors Wynn and Hoving. They base their definitions on key factors like the shared market, organizations, and capital, which are vital in supporting the open source software community. Some widely accepted definitions of open source software ecosystems are:

  • A Software Ecosystem placed in a heterogeneous environment
  • Its boundary is a set of niche players
  • The keystone player is an OSS community around a set of projects in a common platform

Learn more about Open Source Software Ecosystems: Franco, O. Open source software ecosystems: towards a modeling framework

  • Open Source Project Dynamics: Open source project dynamics refers to the complex social and technical interactions that occur within open source communities. This includes things like peer review, community-driven governance, and decentralized decision making. Understanding these dynamics is important for anyone looking to participate in or manage open source projects.

  • Open Works: Open Works refers to the meaning of “Open” with respect to work products and projects that are released into the public domain or under a license recognized by an entity such as, but not limited to, the Open Source Initiative (OSI), the Free Software Foundation GNU, the Creative Commons (CC) or the Open Knowledge Foundation (OKF) with the intent of promoting a robust community of collaboration around the work itself and other work that it may interoperate with. Learn more about Open Works:

  • Software Bill of Materials: A software bill of materials (SBOM) is a nested inventory for software, a list of ingredients that make up software components. Learn more about SBOM at

  • Software Package Data Exchange (SPDX): SPDX is an open standard for software bill of materials (SBOM). SPDX allows the expression of components, licenses, copyrights, security references, and other metadata relating to software. Learn more about SPDX at

  • Software Supply Chain: Software Supply Chai is composed of the components, libraries, tools, and processes used to develop, build, and publish a software artifact. Learn more about the Software supply chain at

As you explore the terms and concepts in this glossary, we encourage you to use the descriptions and links provided. And if you have any suggestions for additional terms or resources that we should include, please don’t hesitate to open an Issue or include new terms by opening a PR!

Last modified August 15, 2023: Rearrange the navs (739861e)