Open-source refers to software whose source code is publicly accessible and may be used, modified, and redistributed under licenses that satisfy the Open Source Definition maintained by the Open Source Initiative. The open-source model emphasizes transparent collaboration, peer review, and community-driven governance, and is often contrasted with the Free Software Foundation’s freedom-centric framing. Licensing spans permissive options such as the MIT License and Apache License 2.0, as well as copyleft licenses like the GNU General Public License. Notable projects include the Linux kernel, PostgreSQL, and the Apache HTTP Server. Development is typically coordinated via distributed version control systems like Git and platforms that facilitate issue tracking, code review, and community contribution. Sustainability models vary, including corporate sponsorship, foundations, paid support, dual licensing, and “open core” approaches. Standards bodies and foundations, such as the Apache Software Foundation and the Linux Foundation, provide legal @stewardship, infrastructure, and community frameworks that enable long-term project health and broad ecosystem interoperability.

Contexts

• #open-source (this is the @Root Memo)