An open-source license is a copyright license for computer software that makes the source code available for everyone to use. This allows end users to review and modify the source code for their own customization and/or troubleshooting needs. Open-source licenses are also commonly free, allowing for modification, redistribution, and commercial use without having to pay the original author. Some open-source licenses only permit modification of the source code for personal use or only permit non-commercial redistribution. All such licenses usually have additional restrictions such as a requirement to preserve the name of the authors and a copyright statement within the code. One popular set of free open-source software licenses are those approved by the Open Source Initiative (OSI) based on their Open Source Definition (OSD).
In production and development, open source is a philosophy, or pragmatic methodology that promotes free redistribution and access to an end product’s design and implementation details. Before the phrase open source became widely adopted, developers and producers used a variety of terms for the concept; open source gained hold with the rise of the Internet, and the attendant need for massive retooling of the computing source code. Opening the source code enabled a self-enhancing diversity of production models, communication paths, and interactive communities. The open-source software movement arose to clarify the environment that the new copyright, licensing, domain, and consumer issues created.
Generically, open source refers to a program in which the source code is available to the general public for use and/or modification from its original design free of charge, i.e., open. Open source code is typically created as a collaborative effort in which programmers improve upon the code and share the changes within the community. Open source sprouted in the technological community as a response to proprietary software owned by corporations.