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Open Source

Open Source

There are three dimensions to the concept of "open source" as it applies to computing. First, open source is a philosophy about computing and sharing programming code to improve the quality of computing. The term "open source" also refers to a wide array of operating systems and applications that have been developed under this philosophy, and, finally, it represents a general approach to the treatment of intellectual property , usually in reference to licensing software or related documentation.

Origins of Open Source Computing

The idea of sharing the source code for computer programs so that the programs can be debugged, modified, or improved is a practice that began in the late 1950s, when IBM provided programmers employed by their customers with access to the source code for applications running on their mainframe computers . The idea of creating source code for the purposes of sharing it can be traced to the early days of the Internet, when programmers wrote and shared source code for the applications that have been fundamental to the development of the Internet. The establishment and workings of the Free Software Foundation (FSF) have also promoted this approach.

The emergence of the Internet provided a global medium through which programmers could exchange source code, documentation, and other information about programming. The Free Software Foundation, which was founded in 1985 and is "dedicated to promoting computer users' right to use, study, copy, modify, and redistribute computer programs," provided not only software (under its GNU Project), but also a social and political framework for advancing knowledge in the field. The foundation promoted the development and use of free software and documentationnot necessarily free of charge, but freely accessible as intellectual propertyand campaigned to increase what its members believe to be the ethical and political issues of freedom in the use of software.

The General Public License

One of the key contributions made by the Free Software Foundation has been to establish the legal basis for free software under U.S. intellectual property law, in the form of the General Public License (GPL). Under the GPL, software is licensed for the purpose of making derivative works, may be distributed without charge, and must be disclosed or distributed in source code form. The essential purpose of the GPL is to create a legal environment that is hospitable to the exchange of source code and programs, and which tends to promote efforts to study, change, or improve computer software. Related or variant licensing schemes include the Lesser GPL (LGPL), the Apache license, the Artistic License, the FreeBSD copyright, the Mozilla Public License, the Netscape Public License, the Sun Community Source License (SCSL), and the Sun Industry Standards License (SISL).

There is considerable controversy in regard to the benefits of the GPL. Its proponents argue that software developed and issued under the GPL is less expensive and ultimately more powerful than proprietary software , because development and testing are open processes. Critics of the GPL claim that open software diminishes incentives to create better software, because it weakens the business models on which the proprietary software industry has been based.

Because of the connotations of "free software," and owing to the anti-business stance of Richard Stallman, the founder of the Free Software Foundation, a less pejorative term, "open source," was adopted during the 1990s. In order to clarify further the circumstances under which software based on the GPL or related licensing schemes is distributed, a group called the Open Source Initiative has formulated the Open Source Definition, which effectively reconciles different licensing schemes, and the Open Source Certification Program, which is aimed at preventing misuse of the phrase "open source" and identifying software that is developed and/or made available under a license that meets the Open Source Definition.

Open Source Development Models

The open source community is divided, at least philosophically, into two factions. The first faction is united by the belief that there is civic, economic, and moral value in the free development and exchange of software. The second faction is defined mainly by a business model, under which open source development is used to reduce the costs of research and development, accelerate the rate at which systems and applications are developed (and debugged), and create open distribution channels that engender broader interest in the software. For some companies, like Red Hat, open source software is the primary basis of their business. For other companies, such as IBM, open source software is employed to create or maintain a product line while lowering direct investment. For many more firms in the software industry, including Microsoft, public domain and open source software is employed to supplement proprietary products and services.

Open Source Computing and the Emergence of Linux

The Free Software Foundation has exerted considerable influence since its establishment, but the emergence of the Linux operating system is the main reason that open source software has become a significant factor in computing. Developed by a Finnish student named Linus Torvalds (and modeled on the UNIX operating system, but without UNIX source code), Linux was initially released in 1991. Owing largely to continued work by Torvalds on the kernel of the operating system, and an integration of the operating system with a suite of utilities developed by the Free Software Foundation's GNU Project, Linux has matured into a sophisticated operating system that now constitutes a legitimate alternative to proprietary systems on the market for server software. In addition, there are several major open source projectsthe most important of them being the GNOME and KDE projectsthat are intended to create desktop environments for Linux that will allow it to challenge both Microsoft Windows and the Macintosh OS as an operating system for personal and corporate desktops.

Other Important Open Source Projects

Linux has received more attention, but there are a number of other important open source projects, including the GNU Project's compilers, libraries, and utilities, its Emacs editor, the Perl and Tcl languages, the FreeBSD operating system, the Apache web server, and sendmail. Of these initiatives, the Apache Projectwhich began in 1995 when a small group of programmers agreed to work collaboratively in order to transform the CERN web server software into a more reliable applicationis arguably the most important, because the Apache web server has played a pivotal role in the growth of the World Wide Web, through the continuous development and distribution of a powerful open source application and an array of modular functions and services. Sendmail is the core service for most of the e-mail transported over the Internet.

Open Source Documentation

An important factor in the development of open source computing has been the application of the open source philosophy to the development and distribution of documentation. Commercial developers and vendors have moved to reduce the amount and quality of documentation that is distributed with operating systems and applications, effectively abandoning the provision of documentation for their products to an expensive, but ineffectual "after market." At the same time, the application of the open source model to documentation has led to the widespread availability of guides and manuals that are accurate, thorough, and up-to-date.

For example, the Linux Documentation Project (LDP) has played a key corollary in the development of Linux. The purpose of the LDP is to promote and coordinate the publication of guides and manuals that support both systems administrators and end users. The LDP serves as a central distribution point for a number of independently produced guides. The LDP also promotes the creation and maintenance of so-called "HOWTOs," briefer guides to specific topics, such as disk partitioning, the configuration of proxy servers, and security.

see also Codes; Coding Techniques; Programming.

Christinger Tomer


Raymond, Eric S. The Cathedral and the Bazaar: Musings on Linux and Open Source by an Accidental Revolutionary. Sebastopol, CA: O'Reilly & Associates, 1999.

Young, Robert, and Wendy Goldman Rohm. Under the Radar: How Red Hat Changed the Software Businessand Took Microsoft by Surprise. Scottsdale, AZ: Coriolis Press, 1999.

Internet Resources

"The Free Software Definition." The GNU Project; Free Software Foundation. <>

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