International Symposium on Software Composition

Open-source software

Open-source software (OSS) is a type of computer software in which source code is released under a license in which the copyright holder grants users the rights to study, change, and distribute the software to anyone and for any purpose. Open-source software may be developed in a collaborative public manner. Open-source software is a prominent example of open collaboration.

Netscape's act prompted Raymond and others to look into how to bring the Free Software Foundation's free software ideas and perceived benefits to the commercial software industry. They concluded that FSF's social activism was not appealing to companies like Netscape, and looked for a way to rebrand the free software movement to emphasize the business potential of sharing and collaborating on software source code. The new term they chose was "open source", which was soon adopted by Bruce Perens, publisher Tim O'Reilly, Linus Torvalds, and others. The Open Source Initiative was founded in February 1998 to encourage use of the new term and evangelize open-source principles.

The Open Source Definition presents an open-source philosophy and further defines the terms of use, 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 (GPL), which "allows free distribution under the condition that further developments and applications are put under the same licence", thus also free.

The Open Source Initiative's (OSI) definition is recognized by several governments internationally as the standard or de facto definition. In addition, many of the world's largest open-source-software projects and contributors, including Debian, Drupal Association, FreeBSD Foundation, Linux Foundation, OpenSUSE Foundation, Mozilla Foundation, Wikimedia Foundation, Wordpress Foundation have committed to upholding the OSI's mission and Open Source Definition through the OSI Affiliate Agreement.

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.

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 licenses 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 violate the licensing conditions, their license disappears, meaning they are infringing copyright. Despite this licensing risk, most commercial software vendors are using open source software in commercial products while fulfilling the license terms, e.g. leveraging the Apache license.

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.

Open source development 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. Open source is not dependent on the company or author that originally created it. Even if the company fails, the code continues to exist and be developed by its users. Also, it uses open standards accessible to everyone; thus, it does not have the problem of incompatible formats that may exist in proprietary software.

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.

Open Source Software Institute is a membership-based, non-profit (501 (c)(6)) organization established in 2001 that promotes the development and implementation of open source software solutions within US Federal, state and local government agencies. OSSI's efforts have focused on promoting adoption of open source software programs and policies within Federal Government and Defense and Homeland Security communities.

Open source software projects are built and maintained by a network of volunteer programmers and are widely used in free as well as commercial products. Prime examples of open-source products are the Apache HTTP Server, the e-commerce platform osCommerce, internet browsers Mozilla Firefox and Chromium (the project where the vast majority of development of the freeware Google Chrome is done) and the full office suite LibreOffice. One of the most successful open-source products is the GNU/Linux operating system, an open-source Unix-like operating system, and its derivative Android, an operating system for mobile devices. In some industries, open source software is the norm.