In production and development, open source as a development model promotes a universal access via a free license to a product’s design or blueprint, and universal redistribution of that design or blueprint, including subsequent improvements to it by anyone. Before the phrase open source became widely adopted, developers and producers used a variety of other terms. 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. Generally, open source refers to a computer program in which the source code is available to the general public for use and/or modification from its original design. Open-source code is typically a collaborative effort where programmers improve upon the source code and share the changes within the community so that other members can help improve it further. Many large formal institutions have sprung up to support the development of the open source movement, including the Apache Software Foundation, which supports projects such as the open source framework behind big data Apache Hadoop and an open-source HTTP server Apache HTTP. The open-source model is based on a more decentralized model of production, in contrast with more centralized models of development such as those typically used in commercial software companies. A main principle of open-source software development is peer production, with products such as source code, “blueprints”, and documentation available to the public at no cost. The open source movement in software began as a response to the limitations of proprietary code, and has since spread across different fields. This model is also used for the development of open-source-appropriate technologies, solar photovoltaic technology and open-source drug discovery.