
A licensing model that makes software freely available for use and modification.Open source is a licensing model that makes software's source code freely available for anyone to use, modify, and distribute. It fosters collaborative development, transparency, and innovation, as seen in projects like Linux, Python, and the Apache web server. For scientists, open source is essential for reproducible research, allowing others to inspect, validate, and build upon computational methods.
The term 'open source' was coined in 1998 by Christine Peterson, though the practice dates back to early hacker culture and the Free Software Movement led by Richard Stallman in the 1980s. The Open Source Initiative formalized the definition in 1998.
Open source licenses (e.g., MIT, GPL) grant users the right to access, modify, and share code, often with the condition that derivative works remain open. Development typically occurs through public repositories, where contributors submit changes that are reviewed and merged by maintainers. This decentralized model leverages collective expertise and peer review to improve software quality and security.
Open source software powers scientific computing (e.g., NumPy, ROOT), data analysis (e.g., R, Jupyter), and machine learning frameworks (e.g., TensorFlow), enabling researchers worldwide to share tools and results.
The Linux kernel, an open source project started by Linus Torvalds in 1991, now runs on everything from smartphones to supercomputers, including the majority of the world's top 500 fastest computers.


