Open source
Open source is a development methodology, which offers practical accessibility to a product's source (goods and knowledge). Some consider open source as one of various possible design approaches, while others consider it a critical strategic element of their operations. Before open source became widely adopted, developers and producers used a variety of phrases to describe the concept; the term open source gained popularity with the rise of the Internet, which provided access to diverse production models, communication paths, and interactive communities.
The open source model of operation and decision making allows concurrent input of different agendas, approaches and priorities, and differs from the more closed, centralized models of development. The principles and practices are commonly applied to the development of source code for software that is made available for public collaboration, and it is usually released as open-source software.

# Society and culture
Open source culture is the creative practice of appropriation and free sharing of found and created content. Examples include collage, found footage film, music, and appropriation art. Open source culture is one in which fixations, works entitled to copyright protection, are made generally available. Participants in the culture can modify those products and redistribute them back into the community or other organizations.
The rise of open-source culture in the 20th century resulted from a growing tension between creative practices that involve appropriation, and therefore require access to content that is often copyrighted, and increasingly restrictive intellectual property laws and policies governing access to copyrighted content. The two main ways in which intellectual property laws became more restrictive in the 20th century were extensions to the term of copyright (particularly in the United States) and penalties, such as those articulated in the Digital Millennium Copyright Act (DMCA), placed on attempts to circumvent anti-piracy technologies.
Although artistic appropriation is often permitted under fair use doctrines, the complexity and ambiguity of these doctrines creates an atmosphere of uncertainty among cultural practitioners. Also, the protective actions of copyright owners create what some call a "chilling effect" among cultural practitioners.
In the late 20th century, cultural practitioners began to adopt the intellectual property licensing techniques of free software and open-source software to make their work more freely available to others, including the Creative Commons.
The idea of an "open source" culture runs parallel to "Free Culture," but is substantively different. Free culture is a term derived from the free software movement, and in contrast to that vision of culture, proponents of OSC maintain that some intellectual property law needs to exist to protect cultural producers. Yet they propose a more nuanced position than corporations have traditionally sought. Instead of seeing intellectual property law as an expression of instrumental rules intended to uphold either natural rights or desirable outcomes, an argument for OSC takes into account diverse goods (as in "the Good life") and ends.
One way of achieving the goal of making the fixations of cultural work generally available is to maximally utilize technology and digital media. As predicted by Moore's law, the cost of digital media and storage plummeted in the late 20th Century. Consequently, the marginal cost of digitally duplicating anything capable of being transmitted via digital media dropped to near zero. Combined with an explosive growth in personal computer and technology ownership, the result is an increase in general population's access to digital media. This phenomenon facilitated growth in open source culture because it allowed for rapid and inexpensive duplication and distribution of culture. Where the access to the majority of culture produced prior to the advent of digital media was limited by other constraints of proprietary and potentially "open" mediums, digital media is the latest technology with the potential to increase access to cultural products. Artists and users who choose to distribute their work digitally face none of the physical limitations that traditional cultural producers have been typically faced with. Accordingly, the audience of an open source culture faces little physical cost in acquiring digital media.
Open source culture precedes Richard Stallman's codification of the concept with the creation of the Free Software Foundation. As the public began to communicate through Bulletin Board Systems (BBS) like FidoNet, places like Sourcery Systems BBS were dedicated to providing source code to Public Domain, Shareware and Freeware programs.
Essentially born out of a desire for increased general access to digital media, the Internet is open source culture's most valuable asset. It is questionable whether the goals of an open source culture could be achieved without the Internet. The global network not only fosters an environment where culture can be generally accessible, but also allows for easy and inexpensive redistribution of culture back into various communities. Some reasons for this are as follows.
First, the Internet allows even greater access to inexpensive digital media and storage. Instead of users being limited to their own facilities and resources, they are granted access to a vast network of facilities and resources, some for free. Sites such as Archive.org offer up free web space for anyone willing to license their work under a Creative Commons license. The resulting cultural product is then available to download for free (generally accessible) to anyone with an Internet connection.
Second, users are granted unprecedented access to each other. Older analog technologies such as the telephone or television have limitations on the kind of interaction users can have. In the case of television there is little, if any interaction between users participating on the network. And in the case of the telephone, users rarely interact with any more than a couple of their known peers. On the Internet, however, users have the potential to access and meet millions of their peers. This aspect of the Internet facilitates the modification of culture as users are able to collaborate and communicate with each other across international and cultural boundaries. The speed in which digital media travels on the Internet in turn facilitates the redistribution of culture.
Through various technologies such as peer-to-peer networks and blogs, cultural producers can take advantage of vast social networks in order to distribute their products. As opposed to traditional media distribution, redistributing digital media on the Internet can be virtually costless. Technologies such as BitTorrent and Gnutella take advantage of various characteristics of the Internet protocol (TCP/IP) in an attempt to totally decentralize file distribution.

## Government
- Open source government  primarily refers to use of open source software technologies in traditional government organizations and government operations such as voting.
- Open politics (sometimes known as Open source politics)  is a term used to describe a political process that uses Internet technologies such as blogs, email and polling to provide for a rapid feedback mechanism between political organizations and their supporters. There is also an alternative conception of the term Open source politics which relates to the development of public policy under a set of rules and processes similar to the Open Source Software movement.
- Open source governance  is similar to open source politics, but it applies more to the democratic process and promotes the freedom of information.

## Ethics
Open Source ethics is split into two strands:
- Open Source Ethics as an Ethical School - Charles Ess and David Berry are researching whether ethics can learn anything from an open source approach. Ess famously even defined the AoIR Research Guidelines as an example of open source ethics.
- Open Source Ethics as a Professional Body of Rules - This is based principally on the computer ethics school, studying the questions of ethics and professionalism in the computer industry in general and software development in particular.

## Media
Open source journalism  referred to the standard journalistic techniques of news gathering and fact checking, and reflected a similar term that was in use from 1992 in military intelligence circles, open source intelligence. It is now commonly used to describe forms of innovative publishing of online journalism, rather than the sourcing of news stories by a professional journalist. In the Dec 25, 2006 issue of TIME magazine this is referred to as user created content and listed alongside more traditional open source projects such as OpenSolaris and Linux.
Weblogs, or blogs, are another significant platform for open source culture. Blogs consist of periodic, reverse chronologically ordered posts, using a technology that makes webpages easily updatable with no understanding of design, code, or file transfer required. While corporations, political campaigns and other formal institutions have begun using these tools to distribute information, many blogs are used by individuals for personal expression, political organizing, and socializing. Some, such as LiveJournal or WordPress, utilize open source software that is open to the public and can be modified by users to fit their own tastes. Whether the code is open or not, this format represents a nimble tool for people to borrow and re-present culture; whereas traditional websites made the illegal reproduction of culture difficult to regulate, the mutability of blogs makes "open sourcing" even more uncontrollable since it allows a larger portion of the population to replicate material more quickly in the public sphere.
Messageboards are another platform for open source culture. Messageboards (also known as discussion boards or forums), are places online where people with similar interests can congregate and post messages for the community to read and respond to. Messageboards sometimes have moderators who enforce community standards of etiquette such as banning users who are spammers. Other common board features are private messages (where users can send messages to one another) as well as chat (a way to have a real time conversation online) and image uploading. Some messageboards use phpBB, which is a free open source package. Where blogs are more about individual expression and tend to revolve around their authors, messageboards are about creating a conversation amongst its users where information can be shared freely and quickly. Messageboards are a way to remove intermediaries from everyday life - for instance, instead of relying on commercials and other forms of advertising, one can ask other users for frank reviews of a product, movie or CD. By removing the cultural middlemen, messageboards help speed the flow of information and exchange of ideas.
OpenDocument is an open document file format for saving and exchanging editable office documents such as text documents (including memos, reports, and books), spreadsheets, charts, and presentations. Organizations and individuals that store their data in an open format such as OpenDocument avoid being locked in to a single software vendor, leaving them free to switch software if their current vendor goes out of business, raises their prices, changes their software, or changes their licensing terms to something less favorable.
Open source movie production is either an open call system in which a changing crew and cast collaborate in movie production, a system in which the end result is made available for re-use by others or in which exclusively open source products are used in the production. The 2006 movie Elephants Dream is said to be the "world's first open movie", created entirely using open source technology.
An open source documentary film has a production process allowing the open contributions of archival material, footage, and other filmic elements, both in unedited and edited form. By doing so, on-line contributors become part of the process of creating the film, helping to influence the editorial and visual material to be used in the documentary, as well as its thematic development. The first open source documentary film to go into production "The American Revolution" ," which will examine the role that WBCN-FM in Boston played in the cultural, social and political changes locally and nationally from 1968 to 1974, is being produced by Lichtenstein Creative Media and the non-profit The Fund for Independent Media. Open Source Cinema is a website to create Basement Tapes, a feature documentary about copyright in the digital age, co-produced by the National Film Board of Canada.
Open Source Filmmaking refers to a form of filmmaking that takes a method of idea formation from open source software, but in this case the 'source' for a film maker is raw unedited footage rather than programming code. It can also refer to a method of filmmaking where the process of creation is 'open' i.e. a disparate group of contributors, at different times contribute to the final piece.
Open-IPTV is IPTV that is not limited to one recording studio, production studio, or cast. Open-IPTV uses the Internet or other means to pool efforts and resources together to create an online community that all contributes to a show.

## Education
Within the academic community, there is discussion about expanding what could be called the "intellectual commons" (analogous to the Creative Commons). Proponents of this view have hailed the Connexions Project at Rice University, OpenCourseWare project at MIT, Eugene Thacker's article on "Open Source DNA", the "Open Source Cultural Database", openwebschool, and Wikipedia as examples of applying open source outside the realm of computer software.
Open source curricula are instructional resources whose digital source can be freely used, distributed and modified.
Another strand to the academic community is in the area of research. Many funded research projects produce software as part of their work. There is an increasing interest in making the outputs of such projects available under an open source license. In the UK the Joint Information Systems Committee (JISC) has developed a policy on open source software. JISC also funds a development service called OSS Watch which acts as an advisory service for higher and further education institutions wishing to use, contribute to and develop open source software.

## Fitness
CrossFit is an open source strength and conditioning fitness movement. Its founder freely shares his methodology and publishes a website with gigabytes of data, information and interactive forums.  CrossFit athletes and instructors share their modifications, adaptations and enhancements. The result has been new CrossFit "flavors" including: CrossFit for Kids, CrossFit for Seniors, CrossFit in the Park, and CrossFit for Combat Athletes. Web posts and CrossFit Journal articles often focus on how to modify the program for specific groups who have only limited access to equipment. Examples include high school track athletes and soldiers in Iraq.  CrossFit athletes also post YouTube videos and invite critiques of their form. 

## Innovation communities
The principle of sharing predates the open source movement; for example, the free sharing of information has been institutionalized in the scientific enterprise since at least the 19th century. Open source principles have always been part of the scientific community. The sociologist Robert K. Merton described the four basic elements of the community - universalism (an international perspective), communism (sharing information), disinterestedness (removing one's personal views from the scientific inquiry) and organized skepticism (requirements of proof and review) that accurately describe the scientific community today. These principles are, in part, complemented by US law's focus on protecting expression and method but not the ideas themselves. There is also a tradition of publishing research results to the scientific community instead of keeping all such knowledge proprietary. One of the recent initiatives in scientific publishing has been open access - the idea that research should be published in such a way that it is free and available to the public. There are currently many open access journals where the information is available for free online, however most journals do charge a fee (either to users or libraries for access). The Budapest Open Access Initiative is an international effort with the goal of making all research articles available for free on the Internet. The National Institutes of Health has recently proposed a policy on "Enhanced Public Access to NIH Research Information." This policy would provide a free, searchable resource of NIH-funded results to the public and with other international repositories six months after its initial publication. The NIH's move is an important one because there is significant amount of public funding in scientific research. Many of the questions have yet to be answered - the balancing of profit vs. public access, and ensuring that desirable standards and incentives do not diminish with a shift to open access.
Farmavita.Net - Community of Pharmaceuticals Executives have recently proposed new business model of Open Source Pharmaceuticals . The project is targeted to development and sharing of know-how for manufacture of essential and life saving medicines. It is mainly dedicated to the countries with less developed economies where local pharmaceutical research and development resources are insufficient for national needs. It will be limited to generic medicines with established use. By the definition, medicinal product have a well-established use if is used for at least 15 years, with recognized efficacy and an acceptable level of safety. In that event, the expensive clinical test and trial results could be replaced by appropriate scientific literature.
Benjamin Franklin was an early contributor eventually donating all his inventions including the Franklin stove, bifocals and the lightning rod to the public domain after successfully profiting off their sales and patents.
New NGO communities are starting to use the open source technology as a tool. One example is the Open Source Youth Network started in 2007 in Lisboa by ISCA members.
Open innovation is also a new emerging concept which advocate putting R&D in a common pool, the Eclipse platform is openly presenting itself as an Open innovation network 

## Arts and recreation
Copyright protection is used in the performing arts and even in athletic activities. Some groups have attempted to remove copyright from such practices.

# The Open Source Definition
The Open Source Definition is used by the Open Source Initiative to determine whether or not a software license can be considered open source. The definition was based on the Debian Free Software Guidelines, written and adapted primarily by Bruce Perens.

# Proliferation of the term
While the term applied originally only to the source code of software, it is now being applied to many other areas such as open source ecology, a movement to decentralize technologies so that any human can use them. However, it is often misapplied to other areas which have different and competing principles, which overlap only partially.
Opponents of the spread of the label open source, including Richard Stallman, argue that the requirements and restrictions ensure the continuation of the effort, and resist attempts to redefine the labels. He argues also that most supporters of open source are actually supporters of much more equitable agreements and support re-integration of derived works and that most contributors do not intend to release their work to others who can extend it, hide the extensions, patent those very extensions, and demand royalties or restrict the use of all other usersall while not violating the open source principles with respect to the initial code they acquired.

# Perens' principles
See The Open Source Definition for the exact operational definition and examples of licenses that satisfy, and do not satisfy, those principles.
Under Perens' definition, open source describes a broad general type of software license that makes source code available to the general public with relaxed or non-existent copyright restrictions. The principles, as stated, say absolutely nothing about trademark or patent use and require absolutely no cooperation to ensure that any common audit or release regime applies to any derived works. It is an explicit feature of open source that it may put no restrictions on the use or distribution by any organization or user.
It forbids this, in principle, to guarantee continued access to derived works even by the major original contributors. In contrast to free software or open content licenses, which are often confused with open source but have much more rigorous rules and conventions, open source deliberately errs in favor of allowing any use by any party whatsoever, and offers few or no means or recourses to prevent a free rider problem or deal with proliferation of bad copies that mislead end users.
Perhaps because of this flexibility, which facilitates large commercial users and vendors, the most successful applications of open source have been in consortium. These use other means such as trademarks to control bad copies and require specific performance guarantees from consortium members to assure re-integration of improvements. Accordingly they do not need potentially conflicting clauses in licenses.
The loose definition has led to a proliferation of licenses that can claim to be open source but which would not satisfy the share alike provision that free software and open content licenses require. A very common license, the Creative Commons CC-by-nc-sa, requires a commercial user to acquire a separate license for-profit use. This is explicitly against the open source principles, as it discriminates against a type of use or user. However, the requirement imposed by free software to reliably redistribute derived works, does not violate these principles. Accordingly, free software and consortium licenses are a type of open source, but open content isn't insofar as it allows such restrictions.

# Non-software use
The principles of open source have been adapted for many other forms of user generated content and technology, including open source hardware.
Supporters of the open content movement advocate some restrictions of use, requirements to share changes, and attribution to other authors of the work.
This culture or ideology takes the view that the principles apply more generally to facilitate concurrent input of different agendas, approaches and priorities, in contrast with more centralized models of development such as those typically used in commercial companies.
Advocates of the open source principles often point to Wikipedia as an example, but Wikipedia has in fact often restricted certain types of use or user, and the GFDL license it uses makes specific requirements of all users that technically violate the open source principles.

# History
Very similar to open standards, researchers with access to the Advanced Research Projects Agency Network (ARPANET) used a process called Request for Comments to develop telecommunication network protocols. Characterized by contemporary open source work, this 1960's collaborative process led to the birth of the Internet in 1969. There are earlier instances of open source movements and free software such as IBM's source releases of its operating systems in the 1960s and the SHARE user group that formed to facilitate the exchange of such software.
The decision by some people in the free software movement to use the label open source came out of a strategy session held at Palo Alto, California, in reaction to Netscape's January 1998 announcement of a source code release for Navigator. The group of individuals at the session included Christine Peterson who suggested open source, Todd Anderson, Larry Augustin, Jon Hall, Sam Ockman, Michael Tiemann and Eric S. Raymond. They used the opportunity before the release of Navigator's source code to free themselves of the ideological and confrontational connotations of the term free software. Netscape licensed and released its code as open source under the Netscape Public License and subsequently under the Mozilla Public License.
The term was given a big boost at an event organized in April 1998 by technology publisher Tim O'Reilly. Originally titled the Freeware Summit and later known as the Open Source Summit, the event brought together the leaders of many of the most important free and open source projects, including Linus Torvalds, Larry Wall, Brian Behlendorf, Eric Allman, Guido van Rossum, Michael Tiemann, Paul Vixie, Jamie Zawinski of Netscape, and Eric Raymond. At that meeting, the confusion caused by the name free software was brought up. Tiemann argued for sourceware as a new term, while Raymond argued for open source. The assembled developers took a vote, and the winner was announced at a press conference that evening. Five days later, Raymond made the first public call to the free software community to adopt the new term. The Open Source Initiative was formed shortly thereafter.
The Open Source Initiative (OSI) formed in February 1998 by Raymond and Perens. With about 20 years of evidence from case histories of closed and open development already provided by the Internet, the OSI continued to present the 'open source' case to commercial businesses. They sought to bring a higher profile to the practical benefits of freely available source code, and wanted to bring major software businesses and other high-tech industries into open source. Perens adapted Debian's Free Software Guidelines to make the The Open Source Definition.

# Widely-used open source products
Open source software (OSS) projects are built and maintained by network of volunteer programmers. Prime examples of open source products are the Apache HTTP Server, the internet address system Internet Protocol, and the internet browser Mozilla Firefox. Yet, one of the most successful programs is the Linux operating system, an open source Unix-like operating system.

# Criticism
The criticisms of the specific Open_Source_Initiative (OSI) principles are dealt with above as part of the definition and differentiation from other terms. The open content movement does not recognize nor endorse the OSI principles and embraces instead mutual share-alike agreements that require derived works to be re-integrated and treated equitably, e.g. not patented or trademarked to the detriment of the individual contributors/creators.
Another criticism of the Open Source movement is that these projects may not be really as self-organizing as their proponents claim. This argument holds that successful Open Source projects frequently have a strong central manager, even if that manager is a volunteer. The article Open Source Projects Manage Themselves? Dream On. by Chuck Connell explains this viewpoint. However this is a criticism of the development model, not of the Open Source itself. Also, the author does not state that self organization surely does not work, just points to the cases when the central management was likely involved.
The legal and cultural criticisms are both addressed as part of a common set of objections and criticisms by those who prefer share-alike as an organizing principle. This includes Creative Commons which simply ignores the OSI principles and endorses licenses that clearly violate them such as CC-by-nc-sa or; Creative Commons, Attribute, Non-Commercial, Share-Alike.
Of the vocal critics Richard Stallman of the Free Software Foundation (FSF)whose GFDL license is used by Wikipedia itself, flatly opposes the term Open Source being applied to what they refer to as free software. Although it's clear that legally free software does qualify as open source, he considers that the category is abusive.  They also oppose the professed pragmatism of the Open Source Initiative, as they fear that the free software ideals of freedom and community are threatened by compromising on the FSF's idealistic standards for software freedom.

# Business models
There are a number of commonly recognized barriers to the adoption of open source software by enterprises. These barriers include the perception that open source licenses are viral, lack of formal support and training, the velocity of change, and a lack of a long term roadmap. The majority of these barriers are risk-related. From the other side, not all proprietary projects disclose exact future plans, not all open source licenses are equally viral and many serious OSS projects (especially operating systems) actually make money from paid support and documentation.
Many business models exist around open source software to provide a 'whole product' to help reduce these risks. The 'whole product' typically includes support, commercial licenses, professional services, training, certification, partner programs, references and use cases. These business models range from 'services only' organizations that do not participate in the development of the software to models where the majority of the software is created by full-time committers that are employed by a central organization. These business models have come into existence recently and their operation is not commonly understood. One model that has been developed to explain this is the Bee Keeper Model
A commonly employed Business Strategy of Commercial Open Source Software Firms is the Dual-License Strategy, as demonstrated by MySQL, Alfresco, and others.