open source

Open source typically refers to software whose source code is made available, enabling use, modification, and redistribution. It is primarily associated with software distributed under licenses that meet the criteria of the Open Source Definition maintained by the Open Source Initiative, which permit anyone to use it for any purpose, although the term is sometimes used more broadly for software distributed with source code under different conditions reflecting divergence over the usage of the term and its precise definition. The concept has also been applied beyond software to other digital resources made available alongside their source files or design documents, such as Open Source Educational Resources, Open-source hardware or open-source film.

The open source model is a decentralized software development model that encourages open collaboration. A main principle of open source software development is peer production, with products such as source code, blueprints, and documentation freely available to the public. The open source movement in software began as a response to the limitations of proprietary code. The model is used for projects such as in open source eCommerce, open source appropriate technology, and open source drug discovery.