Open-source software - AbsoluteAstronomy.com

Open-source software is computer software

Computer software

Computer software, or just software, is a collection of computer programs and related data that provide the instructions for telling a computer what to do and how to do it....

that is available in source code form: the source code

Source code

In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...

and certain other rights normally reserved for copyright

Copyright is a legal concept, enacted by most governments, giving the creator of an original work exclusive rights to it, usually for a limited time...

holders are provided under a software license that permits users to study, change, improve and at times also to distribute the software.

Open source software is very often developed in a public, collaborative

Collaborative software development model

The Collaborative software development model is a style of software development whose focus is on public availability and communication, usually via the Internet.The software development model began widespread adoption with the Linux kernel in 1991....

manner. Open-source software is the most prominent example of open-source

Open source

The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...

development and often compared to (technically defined) user-generated content

User-generated content

User generated content covers a range of media content available in a range of modern communications technologies. It entered mainstream usage during 2005 having arisen in web publishing and new media content production circles...

or (legally defined) open content

Open content

Open content or OpenContent is a neologism coined by David Wiley in 1998 which describes a creative work that others can copy or modify. The term evokes open source, which is a related concept in software....

movements.

A report by the Standish Group states that adoption of open-source software models has resulted in savings of about $60 billion per year to consumers.

Open Source Definition

The Open Source Definition is used by the Open Source Initiative

Open Source Initiative

The Open Source Initiative is an organization dedicated to promoting open source software.The organization was founded in February 1998, by Bruce Perens and Eric S. Raymond, prompted by Netscape Communications Corporation publishing the source code for its flagship Netscape Communicator product...

to determine whether or not a software license can be considered open source.

The definition was based on the Debian Free Software Guidelines

Debian Free Software Guidelines

The Debian Free Software Guidelines is a set of guidelines that the Debian Project uses to determine whether a software license is a free software license, which in turn is used to determine whether a piece of software can be included in Debian...

, written and adapted primarily by Bruce Perens

Bruce Perens

Bruce Perens is a computer programmer and advocate in the open source community. He created the Open Source Definition and published the first formal announcement and manifesto of open source. He co-founded the Open Source Initiative with Eric S...

. They are by no means definitive even as applied to software. Clause 3 is the primary legal difference between free software

Free software

Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...

and open source software as such, free software is stricter in interpreting 3. Clauses 5 and 6 are not a condition of any major open content license regimes, which commonly do restrict types of uses and users; for instance, Creative Commons

Creative Commons

Creative Commons is a non-profit organization headquartered in Mountain View, California, United States devoted to expanding the range of creative works available for others to build upon legally and to share. The organization has released several copyright-licenses known as Creative Commons...

has open content licenses that explicitly forbid commercial use.
11. Upgradation and Patch

Open source software should always come with upgradation and additional plugins should be available to the developer community.

History

The free software movement

Free software movement

The free software movement is a social and political movement with the goal of ensuring software users' four basic freedoms: the freedom to run their software, to study and change their software, and to redistribute copies with or without changes. The alternative terms "software libre", "open...

was launched in 1983. In 1998, a group of individuals advocated that the term free software should be replaced by open source software (OSS) as an expression which is less ambiguous and more comfortable for the corporate world. Software developers may want to publish their software with an open source license, so that anybody may also develop the same software or understand its internal functioning. Open source software generally allows anyone to create modifications of the software, port it to new operating systems and processor architectures, share it with others or, in some cases, market it. Scholars Casson and Ryan have pointed out several policy-based reasons for adoption of open source, in particular, the heightened value proposition from open source (when compared to most proprietary formats) in the following categories:

Security
Affordability
Transparency
Perpetuity
Interoperability
Localisation.

Particularly in the context of local governments (who make software decisions), Casson and Ryan argue that "governments have an inherent responsibility and fiduciary duty to taxpayers" which includes the careful analysis of these factors when deciding to purchase proprietary software or implement an open-source option.

The Open Source Definition

Open Source Definition

The Open Source Definition is a document published by the Open Source Initiative, to determine whether or not a software license can be labeled with the open-source certification mark....

, notably, presents an open source philosophy, and further defines the terms of usage, modification and redistribution of open source software. Software licenses grant rights to users which would otherwise be reserved by copyright law to the copyright holder. Several open source software licenses have qualified within the boundaries of the Open Source Definition. The most prominent and popular example is the GNU General Public License

GNU General Public License

The GNU General Public License is the most widely used free software license, originally written by Richard Stallman for the GNU Project....

(GPL), which “allows free distribution under the condition that further developments and applications are put under the same licence” – thus also free. While open source distribution presents a way to make the source code of a product publicly accessible, the open source licenses allow the authors to fine tune such access.

The open source label came out of a strategy session held on April 7, 1998 in Palo Alto

Palo Alto, California

Palo Alto is a California charter city located in the northwest corner of Santa Clara County, in the San Francisco Bay Area of California, United States. The city shares its borders with East Palo Alto, Mountain View, Los Altos, Los Altos Hills, Stanford, Portola Valley, and Menlo Park. It is...

in reaction to Netscape's January 1998 announcement of a source code release for Navigator

Netscape Navigator

Netscape Navigator was a proprietary web browser that was popular in the 1990s. It was the flagship product of the Netscape Communications Corporation and the dominant web browser in terms of usage share, although by 2002 its usage had almost disappeared...

(as Mozilla

Mozilla

Mozilla is a term used in a number of ways in relation to the Mozilla.org project and the Mozilla Foundation, their defunct commercial predecessor Netscape Communications Corporation, and their related application software....

). A group of individuals at the session included Tim O'Reilly

Tim O'Reilly

Tim O'Reilly is the founder of O'Reilly Media and a supporter of the free software and open source movements.-Life and career:...

, Linus Torvalds

Linus Torvalds

Linus Benedict Torvalds is a Finnish software engineer and hacker, best known for having initiated the development of the open source Linux kernel. He later became the chief architect of the Linux kernel, and now acts as the project's coordinator...

, Tom Paquin, Jamie Zawinski

Jamie Zawinski

Jamie Zawinski , commonly known as jwz, is a former professional American computer programmer responsible for significant contributions to the free software projects Mozilla and XEmacs, and early versions of the Netscape Navigator web browser...

, Larry Wall

Larry Wall

Larry Wall is a programmer and author, most widely known for his creation of the Perl programming language in 1987.-Education:Wall earned his bachelor's degree from Seattle Pacific University in 1976....

, Brian Behlendorf

Brian Behlendorf

Brian Behlendorf is a technologist, computer programmer, and an important figure in the open-source software movement. He was a primary developer of the Apache Web server, the most popular web server software on the Internet, and a founding member of the Apache Group, which later became the Apache...

, Sameer Parekh

Sameer Parekh

Sameer Parekh is best known for being the founder of C2Net Software, Inc.While in high school in Libertyville, Illinois, he published an underground newspaper called The Free Journal, promoting free speech and other libertarian ideas....

, Eric Allman

Eric Allman

Eric Paul Allman is an American computer programmer who developed sendmail and its precursor delivermail in the late 1970s and early 1980s at UC Berkeley.-Education and training:...

, Greg Olson, Paul Vixie

Paul Vixie

Paul Vixie is an American Internet pioneer, the author of several RFCs and well-known Unix software.Vixie attended George Washington High School in San Francisco, California. He received a Ph.D in computer science from Keio University in 2011....

, John Ousterhout

John Ousterhout

John Kenneth Ousterhout is the chairman of Electric Cloud, Inc. and a professor of computer science at Stanford University. He founded Electric Cloud with John Graham-Cumming. Ousterhout previously was a professor of computer science at University of California, Berkeley where he created the Tcl...

, Guido van Rossum

Guido van Rossum

Guido van Rossum is a Dutch computer programmer who is best known as the author of the Python programming language. In the Python community, Van Rossum is known as a "Benevolent Dictator For Life" , meaning that he continues to oversee the Python development process, making decisions where necessary...

, Philip Zimmermann, John Gilmore and Eric S. Raymond

Eric S. Raymond

Eric Steven Raymond , often referred to as ESR, is an American computer programmer, author and open source software advocate. After the 1997 publication of The Cathedral and the Bazaar, Raymond was for a number of years frequently quoted as an unofficial spokesman for the open source movement...

. They used the opportunity before the release of Navigator's source code to clarify a potential confusion caused by the ambiguity of the word "free" in English

English language

English is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...

.

Many people claimed that the birth of the Internet

Internet

The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...

, since 1969, started the open source movement, while others do not distinguish between open source and free software movements.

The Free Software Foundation

Free Software Foundation

The Free Software Foundation is a non-profit corporation founded by Richard Stallman on 4 October 1985 to support the free software movement, a copyleft-based movement which aims to promote the universal freedom to create, distribute and modify computer software...

(FSF), started in 1985, intended the word "free" to mean freedom to distribute (or "free as in free speech") and not freedom from cost (or "free as in free beer"). Since a great deal of free software already was (and still is) free of charge, such free software became associated with zero cost, which seemed anti-commercial.

The Open Source Initiative (OSI) was formed in February 1998 by Eric S. Raymond and Bruce Perens. With at least 20 years of evidence from case histories of closed software development versus open development already provided by the Internet developer community, the OSI presented the 'open source' case to commercial businesses, like Netscape. The OSI hoped that the usage of the label "open source," a term suggested by Peterson of the Foresight Institute

Foresight Institute

The Foresight Institute is a Palo Alto, California-based nonprofit organization for promoting transformative technologies. They sponsor conferences on molecular nanotechnology, publish reports, and produce a newsletter....

at the strategy session, would eliminate ambiguity, particularly for individuals who perceive "free software" as anti-commercial. They sought to bring a higher profile to the practical benefits of freely available source code, and they wanted to bring major software businesses and other high-tech industries into open source. Perens attempted to register "open source" as a service mark

Service mark

A service mark or servicemark is a trademark used in some countries, notably the United States, to identify a service rather than a product. When a service mark is federally registered, the standard registration symbol ® or "Reg U.S. Pat & TM Off" may be used...

for the OSI, but that attempt was impractical by trademark

Trademark

A trademark, trade mark, or trade-mark is a distinctive sign or indicator used by an individual, business organization, or other legal entity to identify that the products or services to consumers with which the trademark appears originate from a unique source, and to distinguish its products or...

standards. Meanwhile, due to the presentation of Raymond's paper to the upper management at Netscape—Raymond only discovered when he read the Press Release, and was called by Netscape CEO Jim Barksdale's PA later in the day—Netscape released its Navigator source code as open source, with favorable results.

Definitions

There are numerous groups who claim ownership of the term "Open Source", but the term has not been trademarked. The Open Source Initiative

Open Source Initiative

's definition is widely recognized as the standard or de facto
De facto
De facto is a Latin expression that means "concerning fact." In law, it often means "in practice but not necessarily ordained by law" or "in practice or actuality, but not officially established." It is commonly used in contrast to de jure when referring to matters of law, governance, or...

definition.

The Open Source Initiative (OSI) was 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

Debian

Debian is a computer operating system composed of software packages released as free and open source software primarily under the GNU General Public License along with other free software licenses. Debian GNU/Linux, which includes the GNU OS tools and Linux kernel, is a popular and influential...

's Free Software

Free software

Guidelines to make The Open Source Definition.

The Open Source Definition

The Open Source Definition is used by the Open Source Initiative

Open Source Initiative

to determine whether 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. Perens did not base his writing on the "four freedoms" of Free Software from the FSF, which were only widely available later.

Perens' 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

Patent

A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....

use and require absolutely no cooperation to ensure that any common audit

Audit

The general definition of an audit is an evaluation of a person, organization, system, process, enterprise, project or product. The term most commonly refers to audits in accounting, but similar concepts also exist in project management, quality management, and energy conservation.- Accounting...

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.

Proliferation of the term

While the term "open source" 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.

Non-software use

The principles of open source have been adapted for many forms of user generated content and technology, including open source hardware

Open source hardware

Open source hardware consists of physical artifacts of technology designed and offered in the same manner as free and open source software . Open source hardware is part of the open source culture movement and applies a like concept to a variety of components. The term usually means that...

.

Supporters of the open content movement advocate some restrictions of use, requirements to share changes, and attribution

Attribution (copyright)

Attribution in copyright law, is the requirement to acknowledge or credit the author of a work which is used or appears in another work. Attribution is required by most copyright and copyleft licenses, such as the GNU Free Documentation License and Creative Commons licenses.Attribution is often...

to other authors of the work.

This “culture” or ideology

Ideology

An ideology is a set of ideas that constitutes one's goals, expectations, and actions. An ideology can be thought of as a comprehensive vision, as a way of looking at things , as in common sense and several philosophical tendencies , or a set of ideas proposed by the dominant class of a society to...

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

Wikipedia

Wikipedia is a free, web-based, collaborative, multilingual encyclopedia project supported by the non-profit Wikimedia Foundation. Its 20 million articles have been written collaboratively by volunteers around the world. Almost all of its articles can be edited by anyone with access to the site,...

as an example, but Wikipedia has in fact often restricted certain types of use or user, and the GFDL license it has historically used makes specific requirements of all users, which technically violates the open source principles.

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

Viral license

Viral license is a pejorative term used to describe a copyright license that allows derivative works only when licensed identically to the original. Licenses of this form include several common open source licenses, such as the GNU General Public License and the Creative Commons ShareAlike licenses...

, 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.

A commonly employed business strategy of commercial open-source software firms is the dual-license Strategy, as demonstrated by Ingres, MySQL

MySQL

MySQL officially, but also commonly "My Sequel") is a relational database management system that runs as a server providing multi-user access to a number of databases. It is named after developer Michael Widenius' daughter, My...

, Alfresco

Alfresco (software)

Alfresco is a Free/Libre enterprise content management system for Microsoft Windows and Unix-like operating systems. Alfresco comes in two flavours. Alfresco Community Edition is free software, LGPL licensed open source and open standards. Alfresco Enterprise Edition is commercially & proprietary...

, and others.

Widely used open source products

Open source software (OSS) projects are built and maintained by a network of volunteer programmers. Prime examples of open source products are the Apache HTTP Server

Apache HTTP Server

The Apache HTTP Server, commonly referred to as Apache , is web server software notable for playing a key role in the initial growth of the World Wide Web. In 2009 it became the first web server software to surpass the 100 million website milestone...

, the e-commerce platform osCommerce

OsCommerce

osCommerce is an e-commerce and online store-management software program. It can be used on any web server that has PHP and MySQL installed. It is available as free software under the GNU General Public License.-History:...

and the internet browser Mozilla Firefox

Mozilla Firefox

Mozilla Firefox is a free and open source web browser descended from the Mozilla Application Suite and managed by Mozilla Corporation. , Firefox is the second most widely used browser, with approximately 25% of worldwide usage share of web browsers...

. One of the most successful open source products is the GNU/Linux

Linux

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

operating system, an open source Unix-like

Unix-like

A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....

operating system. In some fields, open software is the norm, like in VoIP applications with Asterisk (PBX)

Asterisk (PBX)

Asterisk is a software implementation of a telephone private branch exchange ; it was created in 1999 by Mark Spencer of Digium. Like any PBX, it allows attached telephones to make calls to one another, and to connect to other telephone services including the public switched telephone network and...

. Open source standards are not, however, limited to open-source software. For example, Microsoft has also joined the open-source discussion with the adoption of their OpenDocument

OpenDocument

The Open Document Format for Office Applications is an XML-based file format for representing electronic documents such as spreadsheets, charts, presentations and word processing documents....

format as well as creating another open standard, the Office Open XML formats.

Development philosophy

In his 1997 essay The Cathedral and the Bazaar, open source evangelist Eric S. Raymond suggests a model for developing OSS known as the bazaar model. Raymond likens the development of software by traditional methodologies to building a cathedral, "carefully crafted by individual wizards or small bands of mages working in splendid isolation". He suggests that all software should be developed using the bazaar style, which he described as "a great babbling bazaar of differing agendas and approaches."

In the traditional model of development, which he called the cathedral model, development takes place in a centralized way. Roles are clearly defined. Roles include people dedicated to designing (the architects), people responsible for managing the project, and people responsible for implementation. Traditional software engineering follows the cathedral model. Fred P. Brooks

Fred Brooks

Frederick Phillips Brooks, Jr. is a software engineer and computer scientist, best known for managing the development of IBM's System/360 family of computers and the OS/360 software support package, then later writing candidly about the process in his seminal book The Mythical Man-Month...

in his book The Mythical Man-Month
The Mythical Man-Month
The Mythical Man-Month: Essays on Software Engineering is a book on software engineering and project management by Fred Brooks, whose central theme is that "adding manpower to a late software project makes it later"...

advocates this model. He goes further to say that in order to preserve the architectural integrity of a system, the system design should be done by as few architects as possible.

The bazaar model, however, is different. In this model, roles are not clearly defined. Gregorio Robles suggests that software developed using the bazaar model should exhibit the following patterns:

Users should be treated as co-developers: The users are treated like co-developers and so they should have access to the source code of the software. Furthermore users are encouraged to submit additions to the software, code fixes for the software, bug reports, documentation etc. Having more co-developers increases the rate at which the software evolves. Linus's law

Linus's Law

There are two statements named Linus's Law: one by Eric S. Raymond concerning software bug detection by a community, and the other by Linus Torvalds about the motivations of programmers.- By Eric Raymond :...

states, "Given enough eyeballs all bugs are shallow." This means that if many users view the source code, they will eventually find all bugs and suggest how to fix them. Note that some users have advanced programming skills, and furthermore, each user's machine provides an additional testing environment. This new testing environment offers that ability to find and fix a new bug.
Early releases: The first version of the software should be released as early as possible so as to increase one's chances of finding co-developers early.
Frequent integration: Code changes should be integrated (merged into a shared code base) as often as possible so as to avoid the overhead of fixing a large number of bugs at the end of the project life cycle. Some open source projects have nightly builds where integration is done automatically

Continuous integration

In software engineering, continuous integration implements continuous processes of applying quality control — small pieces of effort, applied frequently...

on a daily basis.
Several versions: There should be at least two versions of the software. There should be a buggier version with more features and a more stable version with fewer features. The buggy version (also called the development version) is for users who want the immediate use of the latest features, and are willing to accept the risk of using code that is not yet thoroughly tested. The users can then act as co-developers, reporting bugs and providing bug fixes.
High modularization: The general structure of the software should be modular allowing for parallel development on independent components.
Dynamic decision making structure: There is a need for a decision making structure, whether formal or informal, that makes strategic decisions depending on changing user requirements and other factors. Cf. Extreme programming

Extreme Programming

Extreme programming is a software development methodology which is intended to improve software quality and responsiveness to changing customer requirements...

.

Data suggests, however, that OSS is not quite as democratic as the bazaar model suggests. An analysis of five billion bytes of free/open source code by 31,999 developers shows that 74% of the code was written by the most active 10% of authors. The average number of authors involved in a project was 5.1, with the median at 2.

Licensing

A license defines the rights and obligations that a licensor grants to a licensee. Open Source licenses grant licensees the right to copy, modify and redistribute source code (or content). These licenses may also impose obligations (e.g., modifications to the code that are distributed must be made available in source code form, an author attribution must be placed in a program/ documentation using that Open Source, etc.).

Authors initially derive a right to grant a license to their work based on the legal theory that upon creation of a work the author owns the copyright in that work. What the author/licensor is granting when they grant a license to copy, modify and redistribute their work is the right to use the author’s copyrights. The author still retains ownership of those copyrights, the licensee simply is allowed to use those rights, as granted in the license, so long as they maintain the obligations of the license. The author does have the option to sell/assign, versus license, their exclusive right to the copyrights to their work; whereupon the new owner/assignee controls the copyrights. The ownership of the copyright (the “rights”) is separate and distinct from the ownership of the work (the “thing”) - a person can own a copy of a piece of code (or a copy of a book) without the rights to copy, modify or redistribute copies of it.

When an author contributes code to an Open Source project (e.g., Apache.org) they do so under an explicit license (e.g., the Apache Contributor License Agreement) or an implicit license (e.g., the Open Source license under which the project is already licensing code). Some Open Source projects do not take contributed code under a license, but actually require (joint) assignment of the author’s copyright in order to accept code contributions into the project (e.g., OpenOffice.org and its Joint Copyright Assignment agreement).

Placing code (or content) in the public domain is a way of waiving an author’s (or owner’s) copyrights in that work. No license is granted, and none is needed, to copy, modify or redistribute a work in the public domain.

Examples of free software license / open source licenses include Apache License

Apache License

The Apache License is a copyfree free software license authored by the Apache Software Foundation . The Apache License requires preservation of the copyright notice and disclaimer....

, BSD license, GNU General Public License, GNU Lesser General Public License

GNU Lesser General Public License

The GNU Lesser General Public License or LGPL is a free software license published by the Free Software Foundation . It was designed as a compromise between the strong-copyleft GNU General Public License or GPL and permissive licenses such as the BSD licenses and the MIT License...

, MIT License

MIT License

The MIT License is a free software license originating at the Massachusetts Institute of Technology . It is a permissive license, meaning that it permits reuse within proprietary software provided all copies of the licensed software include a copy of the MIT License terms...

, Eclipse Public License

Eclipse Public License

The Eclipse Public License is an open source software license used by the Eclipse Foundation for its software. It replaces the Common Public License and removes certain terms relating to litigations related to patents....

and Mozilla Public License

Mozilla Public License

The Mozilla Public License is a free and open source software license. Version 1.0 was developed by Mitchell Baker when she worked as a lawyer at Netscape Communications Corporation and version 1.1 at the Mozilla Foundation...

.

The proliferation of open source licenses is one of the few negative aspects of the open source movement because it is often difficult to understand the legal implications of the differences between licenses.With more than 180,000 open source projects available and its more than 1400 unique licenses, the complexity of deciding how to manage open source usage within “closed-source”
commercial enterprises have dramatically increased. Some are home-grown while others are modeled after mainstream FOSS licenses such as Berkeley Software Distribution (“BSD”), Apache, MIT-style (Massachusetts Institute of Technology), or GNU General Public License (“GPL”). In view of this, open source practitioners are starting to use classification schemes in which FOSS licenses are grouped (typically based on the existence and obligations imposed by the copyleft provision; the strength of the copyleft provision).

An important legal milestone for the open source / free software movement was passed in 2008, when the US federal appeals court ruled that free software licences definitely do set legally binding conditions on the use of copyrighted work, and they are therefore enforceable under existing copyright law. As a result, if end-users do violate the licensing conditions, their license disappears, meaning they are infringing copyright.

Funding

Unlike proprietary off-the-shelf software, which comes with restrictive copyright licenses, open-source software can be given away for no charge. This means that its creators cannot require each user to pay a license fee to fund development. Instead, a number of alternative models for funding its development have emerged.

Software can be developed as a consulting project for one or more customers. The customers pay to direct the developers' efforts: to have bugs prioritized and fixed or features added. Companies or independent consultants can also charge for training, installation, technical support

Technical support

Technical support or tech support refers to a range of services by which enterprises provide assistance to users of technology products such as mobile phones, televisions, computers, software products or other electronic or mechanical goods...

, or customization of the software.

Another approach to funding is to provide the software freely, but sell licenses to proprietary add-ons such as data libraries. For instance, an open-source CAD program may require parts libraries which are sold on a subscription or flat-fee basis. Open-source software can also promote the sale of specialized hardware that it interoperates with, as in the case of the Asterisk telephony software, developed by a manufacturer of PC telephony hardware.

Many open-source software projects have begun as research projects within universities, as personal projects of students or professors, or as tools to aid scientific research. The influence of universities and research institutions on open source shows in the number of projects named after their host institutions, such as BSD Unix, CMU Common Lisp, or the NCSA HTTPd

NCSA HTTPd

NCSA HTTPd was a web server originally developed at the NCSA by Robert McCool and others. It was among the earliest web servers developed, following Tim Berners-Lee's CERN httpd, Tony Sanders' Plexus server, and some others. It was for some time the natural counterpart to the Mosaic web browser in...

which evolved into Apache.

Companies may employ developers to work on open-source projects that are useful to the company's infrastructure: in this case, it is developed not as a product to be sold but as a sort of shared public utility. A local bug-fix or solution to a software problem, written by a developer either at a company’s request or to make his/her own job easier, can be released as an open source contribution without costing the company anything. A larger project such as the Linux kernel may have contributors from dozens of companies which use and depend upon it, as well as hobbyist and research developers.

Comparison with closed source

The debate over open source vs. closed source (alternatively called proprietary software

Proprietary software

Proprietary software is computer software licensed under exclusive legal right of the copyright holder. The licensee is given the right to use the software under certain conditions, while restricted from other uses, such as modification, further distribution, or reverse engineering.Complementary...

) is sometimes heated.

One source of conflict is related to economics: Making money through traditional methods, such as sale of the use of individual copies and patent royalty payment (generally called licensing), is more difficult and in many ways against the very concept of open source software.

Some closed-source advocates see open source software as damaging to the market of commercial software. This is one of the many reasons, as mentioned above, that the term free software was replaced with open source — because many company executives could not believe in a product that did not participate economically in a free-market or mixed-market economy.

The counter to this argument is the use of open source software to fuel the market for a separate product or service. For example:

Providing support and installation services; similar to IT Security groups, Linux Distributions, and Systems companies.
Using the software as a stepping stone to sell a higher-end product or service; e.g., OpenOffice.org
OpenOffice.org
OpenOffice.org, commonly known as OOo or OpenOffice, is an open-source application suite whose main components are for word processing, spreadsheets, presentations, graphics, and databases. OpenOffice is available for a number of different computer operating systems, is distributed as free software...

vs. StarOffice
StarOffice
StarOffice, known briefly as Oracle Open Office before its discontinuation in 2010, is a proprietary office suite. It was originally developed by StarDivision which was acquired by Sun Microsystems in 1999...

.
Opensource CRM is the affordable solution for small and medium sized business. e.g./ [inspireCRM] vs. [Microsoft Dynamics]
Cost avoidance / cost sharing: many developers need a product, so it makes sense to share development costs (X Window System
X Window System
The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...

and the Apache web server)

Since open source software is open, defects and security flaws are more easily found. Closed-source advocates argue that this makes it easier for a malicious person to discover security flaws. Further, that there is no incentive for an open-source product to be patched. Open-source advocates argue that this makes it easier also for a patch to be found and that the closed-source argument is security through obscurity

Security through obscurity

Security through obscurity is a pejorative referring to a principle in security engineering, which attempts to use secrecy of design or implementation to provide security...

, which this form of security will eventually fail, often without anyone knowing of the failure. Further, that just because there is not an immediate financial incentive to patch a product, does not mean there is not any incentive to patch a product. Further, if the patch is that significant to the user, having the source code, the user can technically patch the problem themselves. These arguments are hard to prove. However, research indicates that the open-source software - Linux - has a lower percentage of bugs than some commercial software.

Comparison with free software

The main difference is that by choosing one term over the other (i.e. either "open source" or "free software") one lets others know about what one's goals are. As Richard Stallman

Richard Stallman

Richard Matthew Stallman , often shortened to rms,"'Richard Stallman' is just my mundane name; you can call me 'rms'"|last= Stallman|first= Richard|date= N.D.|work=Richard Stallman's homepage...

puts it, "Open source is a development methodology; free software is a social movement."

Critics have said that the term “open source” fosters an ambiguity of a different kind such that it confuses the mere availability of the source with the freedom to use, modify, and redistribute it. Developers have used the alternative terms

Alternative terms for free software

Alternative terms for free software have been a controversial issue among free software users from the late 1990s onwards. Coined in 1983 by Richard Stallman, "free software" is used to describe software which can be used, modified, and redistributed with little or no restriction...

Free/open source Software (FOSS

Foss

Foss may refer toPeople*Foss , people with the last name Foss*Foss Shanahan , New Zealand diplomat*Foss Westcott , English bishop...

), or Free/Libre/open source Software (FLOSS), consequently, to describe open source software which is also free software.

The term “open source” was originally intended to be trademarkable; however, the term was deemed too descriptive, so no trademark exists. The OSI would prefer that people treat Open Source as if it were a trademark, and use it only to describe software licensed under an OSI approved license.

OSI Certified is a trademark licensed only to people who are distributing software licensed under a license listed on the Open Source Initiative

Open Source Initiative

's list.

Open source software and free software are different terms for software which comes with certain rights, or freedoms, for the user. They describe two approaches and philosophies

Philosophy

Philosophy is the study of general and fundamental problems, such as those connected with existence, knowledge, values, reason, mind, and language. Philosophy is distinguished from other ways of addressing such problems by its critical, generally systematic approach and its reliance on rational...

towards free software. Open source and free software (or software libre) both describe software which is free from onerous licensing restrictions. It may be used, copied, studied, modified and redistributed without restriction. Free software is not the same as freeware

Freeware

Freeware is computer software that is available for use at no cost or for an optional fee, but usually with one or more restricted usage rights. Freeware is in contrast to commercial software, which is typically sold for profit, but might be distributed for a business or commercial purpose in the...

, software available at zero price.

The definition of open source software was written to be almost identical to the free software definition. There are very few cases of software that is free software but is not open source software, and vice versa. The difference in the terms is where they place the emphasis. “Free software” is defined in terms of giving the user freedom. This reflects the goal of the free software movement. “Open source” highlights that the source code is viewable to all; proponents of the term usually emphasize the quality of the software and how this is caused by the development models which are possible and popular among free and open source software projects.

Free software licenses are not written exclusively by the FSF. The FSF and the OSI both list licenses which meet their respective definitions of free software or open source software.

The FSF believes that knowledge of the concept of freedom is an essential requirement, insists on the use of the term free, and separates itself from the open source movement.

Open source vs. source-available

Although the OSI definition of "open source software" is widely accepted, a small number of people and organizations use the term to refer to software where the source is available for viewing, but which may not legally be modified or redistributed. Such software is more often referred to as source-available, or as shared source
Shared source
Shared source is an umbrella term covering some of Microsoft's legal mechanisms for software source code distribution. Microsoft's Shared Source Initiative, launched in May 2001, includes a spectrum of technologies and licenses...

, a term coined by Microsoft.

Michael Tiemann

Michael Tiemann

Michael Tiemann is Vice President of Open Source Affairs at Red Hat Inc, as well as President of the Open Source Initiative. He previously was the Chief Technical Officer of Red Hat...

, president of OSI, had criticized companies such as SugarCRM

SugarCRM

SugarCRM is a software company based in Cupertino, California. They produce the web application Sugar, also known as SugarCRM, which is a customer relationship management system that is available in both open source and Commercial open source applications.Sugar's functionality includes sales-force...

for promoting their software as "open source" when in fact it did not have an OSI-approved license. In SugarCRM's case, it was because the software is so-called "badgeware" since it specified a "badge" that must be displayed in the user interface (SugarCRM has since switched to GPLv3). Another example is Scilab

Scilab

Scilab is an open source, cross-platform numerical computational package and a high-level, numerically oriented programming language. Itcan be used for signal processing, statistical analysis, image enhancement, fluid dynamics simulations, numerical optimization, and modeling and simulation of...

, which calls itself "the open source platform for numerical computation" but has a license that forbids commercial redistribution of modified versions. Because OSI does not have a registered trademark for the term "open source", its legal ability to prevent such usage of the term is limited, but Tiemann advocates using public opinion from OSI, customers, and community members to pressure such organizations to change their license or to use a different term.

Pros and cons

Software experts and researchers on open source software have identified several advantages and disadvantages. The main advantage for business is that open source is a good way for business to achieve greater penetration of the market. Companies that offer open source software are able to establish an industry standard and, thus, gain competitive advantage. It has also helped build developer loyalty as developers feel empowered and have a sense of ownership of the end product. Moreover less costs of marketing and logistical services are needed for OSS. It also helps companies to keep abreast of all technology developments. It is a good tool to promote a company's image, including its commercial products. The OSS development approach has helped produce reliable, high quality software quickly and inexpensively. The term “open source” was originally intended to be trademarkable; however, the term was deemed too descriptive, so no trademark exists. Besides, it offers the potential for a more flexible technology and quicker innovation. It is said to be more reliable since it typically has thousands of independent programmers testing and fixing bugs of the software. It is flexible because modular systems allow programmers to build custom interfaces, or add new abilities to it and it is innovative since open source programs are the product of collaboration among a large number of different programmers. The mix of divergent perspectives, corporate objectives, and personal goals speeds up innovation. Moreover free software can be developed in accord with purely technical requirements. It does not require thinking about commercial pressure that often degrades the quality of the software. Commercial pressures make traditional software developers pay more attention to customers' requirements than to security requirements, since such features are somewhat invisible to the customer.

It is sometimes said that the open source development process may not be well defined and the stages in the development process, such as system testing and documentation may be ignored. However this is only true for small (mostly single programmer) projects. Larger, successful projects do define and enforce at least some rules as they need them to make the teamwork possible. In the most complex projects these rules may be as strict as reviewing even minor change by two independent developers.

Not all OSS initiatives have been successful, for example, SourceXchange and Eazel. Software experts and researchers who are not convinced by open source’s ability to produce quality systems identify the unclear process, the late defect discovery and the lack of any empirical evidence as the most important problems (collected data concerning productivity and quality). It is also difficult to design a commercially sound business model around the open source paradigm. Consequently, only technical requirements may be satisfied and not the ones of the market. In terms of security, open source may allow hackers to know about the weaknesses or loopholes of the software more easily than closed-source software. It is depended of control mechanisms in order to create effective performance of autonomous agents who participate in virtual organizations.

Development tools

In OSS development, the participants, who are mostly volunteers, are distributed among different geographic regions, so there is need for tools to aid participants to collaborate in source code development. Often, these tools are also available as OSS.

Revision control

Revision control

Revision control, also known as version control and source control , is the management of changes to documents, programs, and other information stored as computer files. It is most commonly used in software development, where a team of people may change the same files...

systems such as Concurrent Versions System

Concurrent Versions System

The Concurrent Versions System , also known as the Concurrent Versioning System, is a client-server free software revision control system in the field of software development. Version control system software keeps track of all work and all changes in a set of files, and allows several developers ...

(CVS) and later Subversion (svn) and Git

Git (software)

Git is a distributed revision control system with an emphasis on speed. Git was initially designed and developed by Linus Torvalds for Linux kernel development. Every Git working directory is a full-fledged repository with complete history and full revision tracking capabilities, not dependent on...

are examples of tools that help centrally manage the source code files and the changes to those files for a software project.

Utilities that automate testing, compiling, and bug reporting help preserve stability and support of software projects that have numerous developers but no managers, quality controller, or technical support. Building systems that report compilation errors among different platforms include Tinderbox

Tinderbox (software)

Tinderbox is a software suite that provides continuous integration capability. Tinderbox allows developers to manage software builds and to correlate build failures on various platforms and configurations with particular code changes....

. Commonly used bugtrackers include Bugzilla

Bugzilla

Bugzilla is a Web-based general-purpose bugtracker and testing tool originally developed and used by the Mozilla project, and licensed under the Mozilla Public License....

and GNATS

GNATS

GNATS is the GNU project's bug-tracking software. GNATS is free software, distributed under the terms of the GNU General Public License.GNU GNATS is a set of tools for tracking bugs reported by users to a central site. It allows problem report management and communication with users via various means...

.

Tools such as mailing lists, IRC

Internet Relay Chat

Internet Relay Chat is a protocol for real-time Internet text messaging or synchronous conferencing. It is mainly designed for group communication in discussion forums, called channels, but also allows one-to-one communication via private message as well as chat and data transfer, including file...

, and instant messaging

Instant messaging

Instant Messaging is a form of real-time direct text-based chatting communication in push mode between two or more people using personal computers or other devices, along with shared clients. The user's text is conveyed over a network, such as the Internet...

provide means of Internet communication between developers. The Web is also a core feature of all of the above systems. Some sites centralize all the features of these tools as a software development management system, including GNU Savannah

GNU Savannah

GNU Savannah is a project of the Free Software Foundation initiated by Loïc Dachary, which serves as a collaborative software development management system for Free Software projects. Savannah currently offers CVS, GNU arch, Subversion, Git, Mercurial, Bazaar, mailing list, web hosting, file...

, SourceForge

SourceForge

SourceForge Enterprise Edition is a collaborative revision control and software development management system. It provides a front-end to a range of software development lifecycle services and integrates with a number of free software / open source software applications .While originally itself...

, and BountySource

BountySource

BountySource is a collaborative project management service for use by any open-source software with an OSI-approved license. Like other free services and products , BountySource allows for developers to track bugs and feature requests. Unlike the others, BountySource also allows for "bounties" and...

Projects and organizations

One of the benefits of open source software is that there are a wide variety of codes in oss projects for program developers. Without any blocking of this wide and diverse platform, developers create a wide range of projects and organizations. Some of the "more prominent organizations" involved in OSS development include the Apache Software Foundation

Apache Software Foundation

The Apache Software Foundation is a non-profit corporation to support Apache software projects, including the Apache HTTP Server. The ASF was formed from the Apache Group and incorporated in Delaware, U.S., in June 1999.The Apache Software Foundation is a decentralized community of developers...

, creators of the Apache web server; a loose affiliation of developers headed by Linus Torvalds, creators of the Linux

Linux kernel

The Linux kernel is an operating system kernel used by the Linux family of Unix-like operating systems. It is one of the most prominent examples of free and open source software....

operating system kernel; the Eclipse Foundation

Eclipse Foundation

The Eclipse Foundation is a not-for-profit, member supported corporation that hosts the open-source Eclipse Projects and helps cultivate both an open source community and an ecosystem of complementary products and services...

, home of the Eclipse

Eclipse (software)

Eclipse is a multi-language software development environment comprising an integrated development environment and an extensible plug-in system...

software development platform; the Debian Project, creators of the influential Debian GNU/Linux distribution;
the Mozilla Foundation

Mozilla Foundation

The Mozilla Foundation is a non-profit organization that exists to support and provide leadership for the open source Mozilla project. The organization sets the policies that govern development, operates key infrastructure and controls trademarks and other intellectual property...

, home of the Firefox web browser; and OW2, European-born community developing open-source middleware. New organizations tend to have a more sophisticated governance model and their membership is often formed by legal entity members.

Several Open Source programs have become defining entries in their space, including the GIMP

GIMP

GIMP is a free software raster graphics editor. It is primarily employed as an image retouching and editing tool and is freely available in versions tailored for most popular operating systems including Microsoft Windows, Apple Mac OS X, and Linux.In addition to detailed image retouching and...

image editing system; Sun's

Sun Microsystems

Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...

Java

Java (programming language)

Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...

programming language and environment; the MySQL database system; the FreeBSD

FreeBSD

FreeBSD is a free Unix-like operating system descended from AT&T UNIX via BSD UNIX. Although for legal reasons FreeBSD cannot be called “UNIX”, as the direct descendant of BSD UNIX , FreeBSD’s internals and system APIs are UNIX-compliant...

Unix operating system; Sun's

Sun Microsystems

Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...

OpenOffice.org

OpenOffice.org, commonly known as OOo or OpenOffice, is an open-source application suite whose main components are for word processing, spreadsheets, presentations, graphics, and databases. OpenOffice is available for a number of different computer operating systems, is distributed as free software...

office productivity suite; and the Wireshark

Wireshark

Wireshark is a free and open-source packet analyzer. It is used for network troubleshooting, analysis, software and communications protocol development, and education...

network packet sniffer

Packet sniffer

A packet analyzer is a computer program or a piece of computer hardware that can intercept and log traffic passing over a digital network or part of a network...

and protocol analyser.

Open Source development is often performed "live and in public", using services provided for free on the Internet, such as the Launchpad

Launchpad (website)

Launchpad is a web application and website that allow users to develop and maintain software, particularly free software. Launchpad is developed and maintained by Canonical Ltd....

and SourceForge

SourceForge.net

SourceForge is a web-based source code repository. It acts as a centralized location for software developers to control and manage open source software development. The website runs a version of SourceForge Enterprise Edition, forked from the last open-source version available...

web sites, and using tools that are themselves Open Source, including the CVS and Subversion source control systems, and the GNU Compiler Collection

GNU Compiler Collection

The GNU Compiler Collection is a compiler system produced by the GNU Project supporting various programming languages. GCC is a key component of the GNU toolchain...

.

Open Source for America is an effort to raise awareness in the U.S. Federal Government about the benefits of open source software. We hope to encourage the government’s utilization of open source software participation in open source software projects, and incorporation of open source community dynamics to enable transparency.

Mil-OSS is a group dedicated to the advancement of OSS use and creation in the military.

Certification

Certification can help to build higher user confidence. Certification could be applied to the simplest component that can be used by developers to build the simplest module to a whole software system. There have been numerous institutions involving in this area of the open source software including The International Institute of Software Technology / United Nations University (http://www.iist.unu.edu). UNU/IIST is a non-profit research and education institution of The United Nations. It is currently involved in a project known as "The Global Desktop Project". This project aims to build a desktop interface that every end-user is able to understand and interact with, thus crossing the language and cultural barriers. It is drawing huge attention from parties involved in areas ranging from application development to localization. Furthermore, this project will improve developing nations' access to information systems. UNU/IIST aims to achieve this without any compromise in the quality of the software. It believes a global standard can be maintained by introducing certifications and is currently organizing conferences in order to explore frontiers in the field (http://opencert.iist.unu.edu).

Alternatively, assurance models (such as DO178B) have already solved the "certification" approach for software. This approach is tailorable and can be applied to OSS, but only if the requisite planning and execution, design, test and traceability artifacts are generated.

Criticism

The criticisms of the specific Open Source Initiative

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

Share-alike

Share-Alike is a descriptive term used in the Creative Commons project for copyright licenses which include certain copyleft provisions. The Share-Alike license comes in two varieties, CC-BY-SA and CC-BY-NC-SA.-Share-alike license types:...

agreements that require commercial use or the preparation of derivative work

Derivative work

In United States copyright law, a derivative work is an expressive creation that includes major, copyright-protected elements of an original, previously created first work .-Definition:...

s.

Of the vocal critics, Richard Stallman of the FSF, flatly opposes the term “Open Source” being applied to what they refer to as “free software”. Although it is clear that legally free software does qualify as open source, Stallman considers that the category is abusive. Critics also oppose the professed pragmatism of the Open Source Initiative

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.

Increasingly, the consensus term "free and open-source software" is used by the communities at large to describe the common ground between free software and open-source software.

External links

Computerworld
Computerworld
Computerworld is an IT magazine that provides information for senior IT leaders. It is published in many countries around the world under the same or similar names. Its publisher is International Data Group. Computerworld serves the needs of IT management via print and online...

article: Does the open-source development model work for business users?
The Open Source Initiative's
Open Source Initiative
The Open Source Initiative is an organization dedicated to promoting open source software.The organization was founded in February 1998, by Bruce Perens and Eric S. Raymond, prompted by Netscape Communications Corporation publishing the source code for its flagship Netscape Communicator product...

definition of open source
Open Sources: Voices from the Open Source Revolution — an online book containing essays from prominent members of the open source community
Free / Open Source Research Community — Many online research papers about Open Source
FreeOpenSourceSoftware.org - Wiki on Open Source history, organizations, licenses, people, software.
KDE
KDE
KDE is an international free software community producing an integrated set of cross-platform applications designed to run on Linux, FreeBSD, Microsoft Windows, Solaris and Mac OS X systems...

developer Aaron Siego's presentation "How OSS Improves Society" at the 2nd Trans-Pacific Open Source Software Conference in Honolulu, Hawaii, January 2006.
Whence The Source: Untangling the Open Source/Free Software Debate, essay on the differences between Free Software and Open Source, by Thomas Scoville
Thomas Scoville
Thomas Scoville . American humorist, technologist and author best known for chronicling the rise and fall of Silicon Valley during the dot-com boom....
Berry, D M (2004). The Contestation of Code: A Preliminary Investigation into the Discourse of the Free Software and Open Software Movement, Critical Discourse Studies, Volume 1(1).
EU study on adopting FLOSS
Open Source Observatory and Repository
Calls for open source government
http://osdir.com "All things open"

The source of this article is wikipedia, the free encyclopedia. The text of this article is licensed under the GFDL.

Open Source Definition

History

Definitions

The Open Source Definition

Perens' principles

Proliferation of the term

Non-software use

Business models

Widely used open source products

Development philosophy

Licensing

Funding

Comparison with closed source

Comparison with free software

Open source vs. source-available

Pros and cons

Development tools

Projects and organizations

Certification

Criticism

See also

Further reading

Legal and economic aspects

External links