The following outline is provided as an overview of and topical guide to free software and the free software movement:

Free software Free software, libre software, libreware sometimes known as freedom-respecting software is computer software distributed open-source license, under terms that allow users to run the software for any purpose as well as to study, change, distribut ...

–

software Software consists of computer programs that instruct the Execution (computing), execution of a computer. Software also includes design documents and specifications. The history of software is closely tied to the development of digital comput ...

which can be run, studied, examined, modified, and redistributed freely (without any cost). This type of software, which was given its name in 1983, has also come to be known as "

open-source software Open-source software (OSS) is Software, computer software that is released under a Open-source license, license in which the copyright holder grants users the rights to use, study, change, and Software distribution, distribute the software an ...

", "software libre", " FOSS", and "FLOSS". The term "Free" refers to it being unfettered, rather than being free of charge.

Large free software projects

GNU Project The GNU Project ( ) is a free software, mass collaboration project announced by Richard Stallman on September 27, 1983. Its goal is to give computer users freedom and control in their use of their computers and Computer hardware, computing dev ...

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

Berkeley Software Distribution The Berkeley Software Distribution (BSD), also known as Berkeley Unix or BSD Unix, is a discontinued Unix operating system developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berkeley, beginn ...

Free software by type

Free and open-source software packages (by type) * Comparison of free off-line GPS software *

Comparison of free software for audio This comparison of free software for audio lists notable free and open source software for use by sound engineers, audio producers, and those involved in sound recording and reproduction. Audio analysis Converters DJ software Distributi ...

Free statistical software Free statistical software is a practical alternative to commercial packages. Many of the free to use programs aim to be similar in function to commercial packages, in that they are general statistical packages that perform a variety of statistica ...

Free television software Free may refer to: Concept * Freedom, the ability to act or change without constraint or restriction * Emancipate, attaining civil and political rights or equality * Free (''gratis''), free of charge * Gratis versus libre, the difference bet ...

* Free web application software

Free software products

* List of free software project directories * List of formerly proprietary software *

List of Linux distributions This page provides general information about notable Linux distributions in the form of a categorized list. Distributions are organized into sections by the major distribution or package management system they are based on. Debian-based Debi ...

List of Ubuntu-based distributions This page provides general information about notable Linux distributions in the form of a categorized list. Distributions are organized into sections by the major distribution or package management system they are based on. Debian-based Debi ...

* List of open source software packages ** Comparison of open source wireless drivers ** List of open source statistical packages ** List of trademarked open source software *

List of free and open-source Android applications This is a list of notable applications (''apps'') that run on the Android platform which meet guidelines for free software and open-source software. Advertisement blocking Web browsers Office Suites and synchronisation ...

List of free and open-source software packages This is a list of free and open-source software (FOSS) packages, computer software licensed under free software licenses and open-source licenses. Software that fits the Free Software Definition may be more appropriately called free software; ...

* List of free software web applications

Operating system families

* Comparison of open-source operating systems * AROS *

BSD The Berkeley Software Distribution (BSD), also known as Berkeley Unix or BSD Unix, is a discontinued Unix operating system developed and distributed by the Computer Systems Research Group (CSRG) at the University of California, Berkeley, beginni ...

* Darwin * eCos *

FreeDOS FreeDOS (formerly PD-DOS) is a free software operating system for IBM PC compatible computers. It intends to provide a complete MS-DOS-compatible environment for running Legacy system, legacy software and supporting embedded systems. FreeDOS ca ...

* GNU *

Haiku is a type of short form poetry that originated in Japan. Traditional Japanese haiku consist of three phrases composed of 17 Mora (linguistics), morae (called ''On (Japanese prosody), on'' in Japanese) in a 5, 7, 5 pattern; that include a ''kire ...

* Inferno *

Mach The Mach number (M or Ma), often only Mach, (; ) is a dimensionless quantity in fluid dynamics representing the ratio of flow velocity past a Boundary (thermodynamic), boundary to the local speed of sound. It is named after the Austrian physi ...

MINIX MINIX is a Unix-like operating system based on a microkernel Software architecture, architecture, first released in 1987 and written by American-Dutch computer scientist Andrew S. Tanenbaum. It was designed as a clone of the Unix operating syste ...

OpenSolaris OpenSolaris () is a discontinued open-source computer operating system for SPARC and x86 based systems, created by Sun Microsystems and based on Solaris. Its development began in the mid 2000s and ended in 2010. OpenSolaris was developed as ...

* Plan 9 *

ReactOS ReactOS is a Free and open-source software, free and open-source operating system for i586/amd64 personal computers that is intended to be binary-code compatibility, binary-compatible with computer programs and device drivers developed for Wind ...

Open-source software development products

Eclipse An eclipse is an astronomical event which occurs when an astronomical object or spacecraft is temporarily obscured, by passing into the shadow of another body or by having another body pass between it and the viewer. This alignment of three ...

* F# *

Free Pascal Free Pascal Compiler (FPC) is a compiler for the closely related programming-language dialects Pascal and Object Pascal. It is free software released under the GNU General Public License, witexception clausesthat allow static linking against it ...

FreeBASIC FreeBASIC is a FOSS, free and open source multiplatform compiler and programming language based on BASIC licensed under the GNU General Public License, GNU GPL for Microsoft Windows, protected-mode MS-DOS (DOS extender), Linux, FreeBSD and Xbox ...

* Gambas * GCC *

Java Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...

LLVM LLVM, also called LLVM Core, is a target-independent optimizer and code generator. It can be used to develop a Compiler#Front end, frontend for any programming language and a Compiler#Back end, backend for any instruction set architecture. LLVM i ...

* Lua *

NetBeans NetBeans is an integrated development environment (IDE) for Java (programming language), Java. NetBeans allows applications to be developed from a set of modular software components called ''modules''. NetBeans runs on Microsoft Windows, Windows, ...

* Open64 *

Perl Perl is a high-level, general-purpose, interpreted, dynamic programming language. Though Perl is not officially an acronym, there are various backronyms in use, including "Practical Extraction and Reporting Language". Perl was developed ...

PHP PHP is a general-purpose scripting language geared towards web development. It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1993 and released in 1995. The PHP reference implementation is now produced by the PHP Group. ...

* Python *

ROSE A rose is either a woody perennial plant, perennial flowering plant of the genus ''Rosa'' (), in the family Rosaceae (), or the flower it bears. There are over three hundred Rose species, species and Garden roses, tens of thousands of cultivar ...

Ruby Ruby is a pinkish-red-to-blood-red-colored gemstone, a variety of the mineral corundum ( aluminium oxide). Ruby is one of the most popular traditional jewelry gems and is very durable. Other varieties of gem-quality corundum are called sapph ...

* Tcl *

TypeScript TypeScript (abbreviated as TS) is a high-level programming language that adds static typing with optional type annotations to JavaScript. It is designed for developing large applications and transpiles to JavaScript. It is developed by Micr ...

Free software movement

* Alternative terms for free software * Debian Social Contract *

Free-software licence A free-software license is a notice that grants the recipient of a piece of software extensive rights to modify and software distribution, redistribute that software. These actions are usually prohibited by copyright law, but the rights-holde ...

Gratis versus Libre The adjective ''free'' in English is commonly used in one of two meanings: "at no monetary cost" (''gratis'') or "with little or no restriction" (''libre''). This ambiguity can cause issues where the distinction is important, as it often is in ...

Open source Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentrali ...

** Open-source definition **

Open-source software Open-source software (OSS) is Software, computer software that is released under a Open-source license, license in which the copyright holder grants users the rights to use, study, change, and Software distribution, distribute the software an ...

Open-source-software movement The open-source software movement is a social movement that supports the use of open-source licenses for some or all software, as part of the broader notion of open collaboration. The open-source movement was started to spread the concept/idea ...

** Comparison of open source and closed source ** Comparison of open-source software hosting facilities *

Open standard An open standard is a standard that is openly accessible and usable by anyone. It is also a common prerequisite that open standards use an open license that provides for extensibility. Typically, anybody can participate in their development due to ...

Long-term support Long-term support (LTS) is a product lifecycle management policy in which a stable release of computer software is maintained for a longer period of time than the standard edition. The term is typically reserved for open-source software, where it ...

* Software Package Data Exchange

Challenges

Proprietary software Proprietary software is computer software, software that grants its creator, publisher, or other rightsholder or rightsholder partner a legal monopoly by modern copyright and intellectual property law to exclude the recipient from freely sharing t ...

* Proprietary device driver ("binary blobs") * Free and open-source graphics device driver * Proprietary firmware * Secure boot *

Digital rights management Digital rights management (DRM) is the management of legal access to digital content. Various tools or technological protection measures, such as access control technologies, can restrict the use of proprietary hardware and copyrighted works. DRM ...

* License proliferation *

Software patents and free software Opposition to software patents is widespread in the free software community. In response, various mechanisms have been tried to defuse the perceived problem. Positions from the community Community leaders such as Richard Stallman, Alan Cox, Br ...

* SCO–Linux controversies * Mozilla software rebranded by Debian * Open-source software security *

Trusted Computing Trusted Computing (TC) is a technology developed and promoted by the Trusted Computing Group. The term is taken from the field of trusted systems and has a specialized meaning that is distinct from the field of confidential computing. With Trust ...

Free software licenses

Specific licenses

Apache The Apache ( ) are several Southern Athabaskan language-speaking peoples of the Southwestern United States, Southwest, the Southern Plains and Northern Mexico. They are linguistically related to the Navajo. They migrated from the Athabascan ho ...

Artistic Art is a diverse range of culture, cultural activity centered around works of art, ''works'' utilizing Creativity, creative or imagination, imaginative talents, which are expected to evoke a worthwhile experience, generally through an express ...

Beerware Beerware is a tongue-in-cheek software license with permissive terms, which grants the right to do anything with the source code, assuming the license notice is preserved. Description Should the user of the code consider the software usefu ...

Boost Software License Boost is a set of library (computing), libraries for the C++ programming language that provides support for tasks and structures such as linear algebra, pseudorandom number generator, pseudorandom number generation, multithreading, image proces ...

BSD licenses BSD licenses are a family of permissive free software licenses, imposing minimal restrictions on the use and distribution of covered software. This is in contrast to copyleft licenses, which have share-alike requirements. The original BSD lice ...

* CC0 *

GNU General Public License The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first ...

GNU Lesser General Public License The GNU Lesser General Public License (LGPL) is a free-software license published by the Free Software Foundation (FSF). The license allows developers and companies to use and integrate a software component released under the LGPL into their own ...

* ISC license *

MIT License The MIT License is a permissive software license originating at the Massachusetts Institute of Technology (MIT) in the late 1980s. As a permissive license, it puts very few restrictions on reuse and therefore has high license compatibility. Unl ...

Mozilla Public License The Mozilla Public License (MPL) is a free and open-source weak copyleft license for most Mozilla Foundation software such as Firefox and Thunderbird. The MPL is developed and maintained by Mozilla, which seeks to balance the concerns of bo ...

* Ms-PL/RL * WTFPL *

zlib License The zlib license is a permissive software license which defines the terms under which the zlib software library can be distributed. It is also used by many other open-source packages. The libpng library uses a similar license, libpng license, s ...

License types and standards

Comparison of free and open-source software licenses This comparison only covers software licenses which have a linked Wikipedia article for details and which are approved by at least one of the following expert groups: the Free Software Foundation, the Open Source Initiative, the Debian Project and ...

* Contributor License Agreement *

Copyleft Copyleft is the legal technique of granting certain freedoms over copies of copyrighted works with the requirement that the same rights be preserved in derivative works. In this sense, ''freedoms'' refers to the use of the work for any purpose, ...

Debian Free Software Guidelines ''The Open Source Definition'' (OSD) is a policy document published by the Open Source Initiative. Derived from the Debian Free Software Guidelines written by Bruce Perens, the definition is the most common standard for open-source software. ...

* Definition of Free Cultural Works * Free license * The Free Software Definition *

The Open Source Definition ''The Open Source Definition'' (OSD) is a policy document published by the Open Source Initiative. Derived from the Debian Free Software Guidelines written by Bruce Perens, the definition is the most common standard for open-source software. T ...

Open-source license Open-source licenses are software licenses that allow content to be used, modified, and shared. They facilitate free and open-source software (FOSS) development. Intellectual property (IP) laws restrict the modification and sharing of creative ...

* Permissive free software licence *

Public domain The public domain (PD) consists of all the creative work to which no Exclusive exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly Waiver, waived, or may be inapplicable. Because no one holds ...

* Viral license

History of the free software movement

Free Software Foundation The Free Software Foundation (FSF) is a 501(c)(3) non-profit organization founded by Richard Stallman on October 4, 1985. The organisation supports the free software movement, with the organization's preference for software being distributed ...

* SCO-Linux controversies *

Open Source Initiative The Open Source Initiative (OSI) is a California public benefit corporation "actively involved in Open Source community-building, education, and public advocacy to promote awareness and the importance of non-proprietary software". Governance The ...

* History of GNU * History of Haiku *

History of Linux Linux began in 1991 as a personal project by Finnish student Linus Torvalds to create a new free operating system kernel. The resulting Linux kernel has been marked by constant growth throughout its history. Since the initial release of its s ...

* History of the Linux kernel *

Mozilla Mozilla is a free software community founded in 1998 by members of Netscape. The Mozilla community uses, develops, publishes and supports Mozilla products, thereby promoting free software and open standards. The community is supported institution ...

** History of Mozilla Application Suite ** History of Firefox ** History of Mozilla Thunderbird * Timeline of free and open-source software

Events

* List of free-software events

Organizations

* .NET Foundation *

Android Open Source Project Android is an operating system based on a modified version of the Linux kernel and other open-source software, designed primarily for touchscreen-based mobile devices such as smartphones and tablets. Android has historically been developed by ...

Apache Software Foundation The Apache Software Foundation ( ; ASF) is an American nonprofit corporation (classified as a 501(c)(3) organization in the United States) to support a number of open-source software projects. The ASF was formed from a group of developers of the ...

Blender Foundation The Blender Foundation is a Dutch nonprofit organization (Stichting) responsible for the development of Blender (software), Blender, an Open-source software, open-source 3D computer graphics software, 3D content-creation program. The foundation ...

* The Document Foundation *

Eclipse Foundation The Eclipse Foundation AISBL is an independent, Europe-based not-for-profit organization that acts as a steward of the Eclipse open source software development community, with legal jurisdiction in the European Union. It is an organization supp ...

* F Sharp Software Foundation *

Free Software Foundation Europe The Free Software Foundation Europe e.V. (FSFE) is an organization that supports free software and all aspects of the free software movement in Europe, with registered chapters in several European countries. It is a registered voluntary associat ...

** Free Software Foundation of India **

Free Software Foundation Latin America Free Software Foundation Latin America (FSFLA) is the Latin American sister organisation of the Free Software Foundation. It is the fourth sister organisation of FSF, after Free Software Foundation Europe and Free Software Foundation India. It ...

* FreeBSD Foundation *

freedesktop.org freedesktop.org (fd.o), formerly X Desktop Group (XDG), is a project to work on interoperability and shared base technology for free-software desktop environments for the X Window System (X11) and Wayland on Linux and other Unix-like operatin ...

* Free Software Movement of India * GNOME Foundation *

* Google Code * KDE e.V. *

Linux Foundation The Linux Foundation (LF) is a non-profit organization established in 2000 to support Linux development and open-source software projects. Background The Linux Foundation started as Open Source Development Labs in 2000 to standardize and prom ...

Mozilla Foundation The Mozilla Foundation is an American non-profit organization that exists to support and collectively lead the Open-source software, open source Mozilla project. Founded in July 2003, the organization sets the policies that govern development, ...

Open Knowledge Foundation Open Knowledge Foundation (OKF) is a global, non-profit network that promotes and shares information at no charge, including both content and data. It was founded by Rufus Pollock on 20 May 2004 in Cambridge, England. It is incorporated in Engla ...

* Open Source Geospatial Foundation *

* Outercurve Foundation *

Software Freedom Conservancy Software Freedom Conservancy, Inc. (also known as "Conservancy") is an organization that provides a Nonprofit organization, non-profit home, infrastructure support, and legal support for free software, free and open source software projects. The ...

SourceForge SourceForge is a web service founded by Geoffrey B. Jeffery, Tim Perdue, and Drew Streib in November 1999. SourceForge provides a centralized software discovery platform, including an online platform for managing and hosting open-source soft ...

Symbian Foundation The Symbian Foundation was a non-profit organisation that stewarded the Symbian operating system for mobile phones which previously had been owned and licensed by Symbian Ltd. Symbian Foundation never directly developed the platform, but evange ...

* X.Org Foundation * Xiph.Org Foundation *

XMPP Standards Foundation XMPP Standards Foundation (XSF) is the foundation in charge of the standardization of the protocol extensions of Extensible Messaging and Presence Protocol, XMPP, the open standard of instant messaging and presence of the Internet Engineering Ta ...

Persons influential in the free software movement

Well known scholars

Lawrence Lessig Lester Lawrence "Larry" Lessig III (born June 3, 1961) is an American legal scholar and political activist. He is the Roy L. Furman Professor of Law at Harvard Law School and the former director of the Edmond J. Safra Center for Ethics at Harvar ...

* John Gilmore *

Eben Moglen Eben Moglen (born July 13, 1959) is an American legal scholar and historian who is a professor of law and legal history at Columbia University, and is the founder, Director-Counsel and Chairman of Software Freedom Law Center. Biography Moglen sta ...

Eric S. Raymond Eric Steven Raymond (born December 4, 1957), often referred to as ESR, is an American software developer, open-source software advocate, and author of the 1997 essay and 1999 book ''The Cathedral and the Bazaar''. He wrote a guidebook for the R ...

Other leading personalities

* Rick Adams *

Eric Allman Eric Paul Allman (born September 2, 1955) is an American computer programmer who developed sendmail and its precursor delivermail in the late 1970s and early 1980s at UC Berkeley. In 1998, Allman and Greg Olson co-founded the company Sendmail ...

Brian Behlendorf Brian Behlendorf (born March 30, 1973) is an American technologist, executive, computer programmer and leading figure in the open-source software movement. He was a primary developer of the Apache Web server, the most popular web server software ...

* Keith Bostic * Alan Cox * Miguel de Icaza * Theo de Raadt *

Jim Gettys Jim Gettys (born 15 October 1953) is an American computer programmer. Activity Gettys worked at Digital Equipment Corporation, DEC's Cambridge Research Laboratory. He is one of the original developers of the X Window System at MIT and worked ...

* Jon Hall * Jordan Hubbard * Lynne Jolitz * William Jolitz *

Rasmus Lerdorf Rasmus Lerdorf (; born 22 November 1968) is a Danish-Canadian programmer. He co-authored and inspired the PHP scripting language, authoring the first two versions of the language and participating in the development of later versions led by a g ...

* Marshall Kirk McKusick * Bram Moolenaar * Ian Murdock *

Tim O'Reilly Timothy O'Reilly (born 6 June 1954) is an Irish-American author and publisher, who is the founder of O'Reilly Media (formerly O'Reilly & Associates). He popularised the terms open source and Web 2.0. Education and early life Born in County Co ...

* Keith Packard * Brian Paul *

Bruce Perens Bruce Perens (born around 1958) is an American computer programmer and advocate in the free software movement. He created ''The Open Source Definition'' and published the first formal announcement and manifesto of open source. He co-founded the ...

* Bob Scheifler *

Mark Shuttleworth Mark Richard Shuttleworth (born 18 September 1973) is a South African and British entrepreneur, founder and CEO of Canonical, the company behind the Ubuntu Linux operating system. In 2002, Shuttleworth became the first African to travel to spa ...

Richard Stallman Richard Matthew Stallman ( ; born March 16, 1953), also known by his initials, rms, is an American free software movement activist and programmer. He campaigns for software to be distributed in such a manner that its users have the freedom to ...

Linus Torvalds Linus Benedict Torvalds ( , ; born 28 December 1969) is a Finnish software engineer who is the creator and lead developer of the Linux kernel. He also created the distributed version control system Git. He was honored, along with Shinya Yam ...

* Andrew Tridgell *

Guido van Rossum Guido van Rossum (; born 31 January 1956) is a Dutch programmer. He is the creator of the Python programming language, for which he was the " benevolent dictator for life" (BDFL) until he stepped down from the position on 12 July 2018. He ...

Larry Wall Larry Arnold Wall (born September 27, 1954) is an American computer programmer, linguist, and author known for creating the Perl programming language and the patch tool. Early life and education Wall grew up in Los Angeles and Bremerton, Wash ...

External links

The Free Software Definition

Transcripts about Free Software
by FSFE
Free Software Magazine
which bills itself as "a free magazine for the free software world."
Free cultural works definition

FLOSSWorld - Free/Libre/Open-Source Software: Worldwide impact study
to find out more about the recently announced European Union funded study.

by Robert J. Chassell {{Outline footer *