Free and open-source software (FOSS) is software that can be classified as both free software and open-source software.[a] That is, anyone is freely licensed to use, copy, study, and change the software in any way, and the source code is openly shared so that people are encouraged to voluntarily improve the design of the software. This is in contrast to proprietary software, where the software is under restrictive copyright licensing and the source code is usually hidden from the users.
FOSS maintains the software user's civil liberty rights (see the Four Essential Freedoms, below). Other benefits of using FOSS can include decreased software costs, increased security and stability (especially in regard to malware), protecting privacy, education, and giving users more control over their own hardware. Free and open-source operating systems such as Linux and descendants of BSD are widely utilized today, powering millions of servers, desktops, smartphones (e.g. Android), and other devices. Free-software licenses and open-source licenses are used by many software packages. The free-software movement and the open-source software movement are online social movements behind widespread production and adoption of FOSS.
"Free and open-source software" (FOSS) is an umbrella term for software that is simultaneously considered both Free software and open-source software. FOSS (free and open-source software) allows the user to inspect the source code and provides a high level of control of the software's functions compared to proprietary software. The term "free software" does not refer to the monetary cost of the software at all, but rather whether the license maintains the software user's civil liberties ("free” as in “free speech,” not as in “free beer”). There are a number of related terms and abbreviations for free and open-source software (FOSS or F/OSS), or free/libre and open-source software (FLOSS or F/LOSS -- FLOSS is the FSF-preferred term).
Although there is almost a complete overlap between free-software licenses and open-source-software licenses, there is a strong philosophical disagreement between the advocates of these two positions. The terminology of FOSS or "Free and Open-source software" was created to be a neutral on these philosophical disagreements between the FSF and OSI and have a single unified term that could refer to both concepts.
As the Free Software Foundation (FSF) explains the philosophical difference between free software and open-source software: "The two terms describe almost the same category of software, but they stand for views based on fundamentally different values. Open-source is a development methodology; free software is a social movement. For the free-software movement, free software is an ethical imperative, essential respect for the users' freedom. By contrast, the philosophy of open-source considers issues in terms of how to make software “better”—in a practical sense only." In parallel to this the Open Source Initiative (OSI) considers many free-software licenses to also be open source. These include the latest versions of the FSF's three main licenses: the GPL, the Lesser General Public License (LGPL), and the GNU Affero General Public License (AGPL).
Richard Stallman's Free Software Definition, adopted by the Free Software Foundation (FSF), defines free software as a matter of liberty not price, and it upholds the Four Essential Freedoms. The earliest-known publication of the definition of his free-software idea was in the February 1986 edition of the FSF's now-discontinued GNU's Bulletin publication. The canonical source for the document is in the philosophy section of the GNU Project website. As of August 2017, it is published there in 40 languages.
To meet the definition of "free software", the FSF requires the software's licensing rights what the FSF respect the civil liberties / human rights of what the FSF calls the software user's "Four Essential Freedoms".
The open-source-software definition is used by the Open Source Initiative (OSI) to determine whether a software license qualifies for the organization's insignia for Open-source software. 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 Essential Freedoms of free software from the Free Software Foundation, which were only later available on the web. Perens subsequently stated that he felt Eric Raymond's promotion of Open-source unfairly overshadowed the Free Software Foundation's efforts and reaffirmed his support for Free software. In the following 2000s, he spoke about open source again.
In the 1950s through the 1980s, it was common for computer users to have the source code for all programs they used, and the permission and ability to modify it for their own use. Software, including source code, was commonly shared by individuals who used computers, often as public domain software. Most companies had a business model based on hardware sales, and provided or bundled software with hardware, free of charge.
By the late 1960s, the prevailing business model around software was changing. A growing and evolving software industry was competing with the hardware manufacturer's bundled software products; rather than funding software development from hardware revenue, these new companies were selling software directly. Leased machines required software support while providing no revenue for software, and some customers who were able to better meet their own needs did not want the costs of software bundled with hardware product costs. In United States vs. IBM, filed January 17, 1969, the government charged that bundled software was anticompetitive. While some software was still being provided without monetary cost and license restriction, there was a growing amount of software that was only at a monetary cost with restricted licensing. In the 1970s and early 1980s, some parts of the software industry began using technical measures (such as distributing only binary copies of computer programs) to prevent computer users from being able to use reverse engineering techniques to study and customize software they had paid for. In 1980, the copyright law was extended to computer programs in the United States—previously, computer programs could be considered ideas, procedures, methods, systems, and processes, which are not copyrightable.
In 1983, Richard Stallman, longtime member of the hacker community at the MIT Artificial Intelligence Laboratory, announced the GNU project, saying that he had become frustrated with the effects of the change in culture of the computer industry and its users. Software development for the GNU operating system began in January 1984, and the Free Software Foundation (FSF) was founded in October 1985. An article outlining the project and its goals was published in March 1985 titled the GNU Manifesto. The manifesto included significant explanation of the GNU philosophy, Free Software Definition and "copyleft" ideas. The FSF takes the position that the fundamental issue Free software addresses is an ethical one—to ensure software users can exercise what it calls "The Four Essential Freedoms".
The Linux kernel, created by Linus Torvalds, was released as freely modifiable source code in 1991. Initially, Linux was not released under either a Free software or an Open-source software license. However, with version 0.12 in February 1992, he relicensed the project under the GNU General Public License.
FreeBSD and NetBSD (both derived from 386BSD) were released as Free software when the USL v. BSDi lawsuit was settled out of court in 1993. OpenBSD forked from NetBSD in 1995. Also in 1995, The Apache HTTP Server, commonly referred to as Apache, was released under the Apache License 1.0.
In 1997, Eric Raymond published The Cathedral and the Bazaar, a reflective analysis of the hacker community and Free software principles. The paper received significant attention in early 1998, and was one factor in motivating Netscape Communications Corporation to release their popular Netscape Communicator Internet suite as Free software. This code is today better known as Mozilla Firefox and Thunderbird.
Netscape's act prompted Raymond and others to look into how to bring the FSF'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 name they chose was "Open-source", and quickly Bruce Perens, publisher Tim O'Reilly, Linus Torvalds, and others signed on to the rebranding. The Open Source Initiative was founded in February 1998 to encourage the use of the new term and evangelize open-source principles.
While the Open Source Initiative sought to encourage the use of the new term and evangelize the principles it adhered to, commercial software vendors found themselves increasingly threatened by the concept of freely distributed software and universal access to an application's source code. A Microsoft executive publicly stated in 2001 that "Open-source is an intellectual property destroyer. I can't imagine something that could be worse than this for the software business and the intellectual-property business." This view perfectly summarizes the initial response to FOSS by some software corporations. For many years FOSS played a niche role outside of the mainstream of private software development. However the success of FOSS Operating Systems such as Linux, BSD and the companies based on FOSS such as Red Hat, has changed the software industry's attitude and there has been a dramatic shift in the corporate philosophy concerning the development of Free and Open-source software (FOSS).
Users of FOSS benefit from the Four Essential Freedoms to make unrestricted use of, and to study, copy, modify, and redistribute such software with or without modification. If they would like to change the functionality of software they can bring about changes to the code and, if they wish, distribute such modified versions of the software or often − depending on the software's decision making model and its other users − even push or request such changes to be made via updates to the original software.
Manufacturers of proprietary, closed-source software are sometimes pressured to building in backdoors or other covert, undesired features into their software. Instead of having to trust software vendors users of FOSS can inspect and verify the source code themselves and can put trust on a community of volunteers and users. As proprietary code is typically hidden from public view, only the vendors themselves and hackers may be aware of any vulnerabilities in them while FOSS involves as many people as possible for exposing bugs quickly.
FOSS is often free of charge although donations are often encouraged. This also allows users to better test and compare software.
FOSS allows for better collaboration among various parties and individuals with the goal of developing the most efficient software for its users or use-cases while proprietary software is typically meant to generate profits. Furthermore, in many cases more organizations and individuals contribute to such projects than to proprietary software. It has been shown that technical superiority is typically the primary reason why companies choose open source software.
According to Linus's Law the more people who can see and test a set of code, the more likely any flaws will be caught and fixed quickly. However, this does not guarantee a high level of participation. Having a grouping of full-time professionals behind a commercial product can in some cases be superior to FOSS.
Furthermore, publicized source code might make it easier for hackers to find vulnerabilities in it and write exploits. This however assumes that such malicious hackers are more effective than white hat hackers which responsibly disclose or help fix the vulnerabilities, that no code leaks or exfiltrations occur and that reverse engineering of proprietary code is a hindrance of significance for malicious hackers.
Sometimes, FOSS is not compatible with proprietary hardware or specific software. This is often due to manufacturers obstructing FOSS such as by not disclosing the interfaces or other specifications needed for members of the FOSS movement to write drivers for their hardware − for instance as they wish customers to run only their own proprietary software or as they might benefit from partnerships.
While FOSS can be superior to proprietary equivalents in terms of software features and stability, in many cases FOSS has more unfixed bugs and missing features when compared to similar commercial software. This varies per case and usually depends on the level of interest and participation in a FOSS project. Furthermore, unlike with typical commercial software missing features and bugfixes can be implemented by any party that has the relevant motivation, time and skill to do so.
There is often less certainty in FOSS projects gaining the required resources / participation for continued development than commercial software backed by companies. However companies also often abolish projects for being unprofitable and often large companies rely on and hence co-develop open source software.
Linux may require more effort or technical knowledge to set up and maintain.
|Brazil||In 2006, the Brazilian government has simultaneously encouraged the distribution of cheap computers running Linux throughout its poorer communities by subsidizing their purchase with tax breaks.|
|Ecuador||In April 2008, Ecuador passed a similar law, Decree 1014, designed to migrate the public sector to Libre Software.|
|France||In March 2009, the French Gendarmerie Nationale announced it will totally switch to Ubuntu by 2015. The Gendarmerie began its transition to open source software in 2005 when it replaced Microsoft Office with OpenOffice.org across the entire organization. In September 2012, the French Prime Minister laid down a set of action-oriented recommendations about using open-source in the French public administration. These recommendations are published in a document based on the works of an inter-ministerial group of experts. This document stops some orientations like establishing an actual convergence on open-source stubs, activating a network of expertise about converging stubs, improving the support of open-source software, contributing to selected stubs, following the big communities, spreading alternatives to the main commercial solutions, tracing the use of open-source and its effects, developing the culture of use of the open-source licenses in the developments of public information systems. One of the aim of this experts groups is also to establish lists of recommended open-source software to use in the French public administration.|
|Germany||In the German City of Munich, conversion of 15,000 PCs and laptops from Microsoft Windows-based operating systems to a Debian-based Linux environment called LiMux spanned the ten years of 2003 to 2013. After successful completion of the project, more than 80% of all computers were running Linux. On November 13, 2017 The Register reported that Munich is planning to revert to Windows 10 by 2020.|
|India||The Government of Kerala, India, announced its official support for FOSS software in its State IT Policy of 2001, which was formulated after the first-ever Free software conference in India, Freedom First!, held in July 2001 in Trivandrum, the capital of Kerala. In 2009, Government of Kerala started the International Centre for Free and Open Source Software (ICFOSS). In March 2015 the Indian government announced a policy on adoption of FOSS.|
|Italy||The Italian military is transitioning to LibreOffice and the Open Document Format (ODF). The Ministry of Defence will over the next year-and-a-half install this suite of office productivity tools on some 150,000 PC workstations - making it Europe’s second largest LibreOffice implementation. The switch was announced on September 15, 2015, by the LibreItalia Association. By June 23, 2016, 6 thousand stations have been migrated. E-learning military platform.|
|Jordan||In January 2010, the Government of Jordan announced a partnership with Ingres Corporation (now named Actian), an open source database management company based in the United States, to promote open-source software use, starting with university systems in Jordan.|
|Malaysia||Malaysia launched the "Malaysian Public Sector Open Source Software Program", saving millions on proprietary software licenses until 2008.|
|Peru||In 2005 the Government of Peru voted to adopt open source across all its bodies. The 2002 response to Microsoft's critique is available online. In the preamble to the bill, the Peruvian government stressed that the choice was made to ensure that key pillars of democracy were safeguarded: "The basic principles which inspire the Bill are linked to the basic guarantees of a state of law."|
|Uganda||In September 2014, the Uganda National Information Technology Authority (NITA-U) announced a call for feedback on an Open Source Strategy & Policy at a workshop in conjunction with the ICT Association of Uganda (ICTAU).|
|United States||In February 2009, the United States White House moved its website to Linux servers using Drupal for content management. In August 2016, the United States government announced a new federal source code policy which mandates that at least 20% of custom source code developed by or for any agency of the federal government be released as open-source software (OSS). In addition, the policy requires that all source code be shared between agencies. The public release is under a three-year pilot program and agencies are obliged to collect data on this pilot to gauge its performance. The overall policy aims to reduce duplication, avoid vendor 'lock-in', and stimulate collaborative development. A new website code|
|Venezuela||In 2004, a law in Venezuela (Decree 3390) went into effect, mandating a two-year transition to open source in all public agencies. As of June 2009, the transition was still under way.|
In 2017, the European Commission stated that "EU institutions should become open source software users themselves, even more than they already are" and listed open source software as one of the nine key drivers of innovation, together with big data, mobility, cloud computing and the internet of things.
While copyright is the primary legal mechanism that FOSS authors use to ensure license compliance for their software, other mechanisms such as legislation, patents, and trademarks have implications as well. In response to legal issues with patents and the Digital Millennium Copyright Act (DMCA), the Free Software Foundation released version 3 of its GNU Public License in 2007 that explicitly addressed the DMCA and patent rights.
After the development of the GNU GPLv3 in 2007, the FSF (as the copyright holder of many pieces of the GNU system) updated many of the GNU programs' licenses from GPLv2 to GPLv3. On the other hand, the adoption of the new GPL version was heavily discussed in the FOSS ecosystem, several projects decided against upgrading. For instance the linux kernel, the BusyBox project, AdvFS, Blender, and as also the VLC media player decided against adopting the GPLv3.
Apple, a user of GCC and a heavy user of both DRM and patents, switched the compiler in its Xcode IDE from GCC to Clang, which is another FOSS compiler but is under a permissive license. LWN speculated that Apple was motivated partly by a desire to avoid GPLv3. The Samba project also switched to GPLv3, so Apple replaced Samba in their software suite by a closed-source, proprietary software alternative.
Leemhuis criticizes the prioritization of skilled developers who − instead of fixing issues in popular applications and desktop environments − create new, mostly redundant software to gain fame and fortune.
He also criticizes notebook manufacturers for optimizing their own products only privately or creating workarounds instead of helping fix the actual causes of the many issues with Linux on notebooks such as the unnecessary power consumption.
Oracle in turn purchased Sun in January, 2010, acquiring their copyrights, patents, and trademarks. Thus, Oracle became the owner of both the most popular proprietary database and the most popular open-source database. Oracle's attempts to commercialize the open-source MySQL database have raised concerns in the FOSS community. Partly in response to uncertainty about the future of MySQL, the FOSS community forked the project into new database systems outside of Oracle's control. These include MariaDB, Percona, and Drizzle. All of these have distinct names; they are distinct projects and cannot use the trademarked name MySQL.
In August, 2010, Oracle sued Google, claiming that its use of Java in Android infringed on Oracle's copyrights and patents. The Oracle v. Google case ended in May 2012, with the finding that Google did not infringe on Oracle's patents, and the trial judge ruled that the structure of the Java APIs used by Google was not copyrightable. The jury found that Google infringed a small number of copied files, but the parties stipulated that Google would pay no damages. Oracle appealed to the Federal Circuit, and Google filed a cross-appeal on the literal copying claim.
By defying ownership regulations in the construction and use of information − a key area of contemporary growth − the Free/Open Source Software (FOSS) movement counters neoliberalism and privatization in general.
By realizing the historical potential of an "economy of abundance" for the new digital world FOSS may lay down a plan for political resistance or show the way towards a potential transformation of capitalism.
According to Yochai Benkler, Jack N. and Lillian R. Berkman Professor for Entrepreneurial Legal Studies at Harvard Law School, free software is the most visible part of a new economy of commons-based peer production of information, knowledge, and culture. As examples, he cites a variety of FOSS projects, including both free software and open-source.
While IBM's policy of withholding source code for selected software products has already marked its second anniversary, users are only now beginning to cope with the impact of that decision. But whether or not the advent of object-code-only products has affected their day-to-day DP operations, some users remain angry about IBM's decision. Announced in February 1983, IBM's object-code-only policy has been applied to a growing list of Big Blue system software products
Currently the decision to move from GPL v2 to GPL v3 is being hotly debated by many open source projects. According to Palamida, a provider of IP compliance software, there have been roughly 2489 open source projects that have moved from GPL v2 to later versions.
Also note that the only valid version of the GPL as far as the kernel is concerned is _this_ particular version of the license (ie v2, not v2.2 or v3.x or whatever), unless explicitly otherwise stated.
"In some ways, Linux was the project that really made the split clear between what the FSF is pushing which is very different from what open source and Linux has always been about, which is more of a technical superiority instead of a -- this religious belief in freedom," Torvalds told Zemlin. So, the GPL Version 3 reflects the FSF's goals and the GPL Version 2 pretty closely matches what I think a license should do and so right now, Version 2 is where the kernel is."
Since BusyBox can be found in so many embedded systems, it finds itself at the core of the GPLv3 anti-DRM debate. [...]The real outcomes, however, are this: BusyBox will be GPLv2 only starting with the next release. It is generally accepted that stripping out the "or any later version" is legally defensible, and that the merging of other GPLv2-only code will force that issue in any case
Don't invent a straw man argument please. I consider licensing BusyBox under GPLv3 to be useless, unnecessary, overcomplicated, and confusing, and in addition to that it has actual downsides. 1) Useless: We're never dropping GPLv2.
[Blender's Toni Roosendaal:] "Blender is also still "GPLv2 or later". For the time being we stick to that, moving to GPL 3 has no evident benefits I know of."
In 2001, VLC was released under the OSI-approved GNU General Public version 2, with the commonly-offered option to use "any later version" thereof (though there was not any such later version at the time). Following the release by the Free Software Foundation (FSF) of the new version 3 of its GNU General Public License (GPL) on the 29th of June 2007, contributors to the VLC media player, and other software projects hosted at videolan.org, debated the possibility of updating the licensing terms for future version of the VLC media player and other hosted projects, to version 3 of the GPL. [...] There is strong concern that these new additional requirements might not match the industrial and economic reality of our time, especially in the market of consumer electronics. It is our belief that changing our licensing terms to GPL version 3 would currently not be in the best interest of our community as a whole. Consequently, we plan to keep distributing future versions of VLC media player under the terms of the GPL version 2.
The Academic Free License (AFL) is a permissive free software license written in 2002 by Lawrence E. Rosen, a former general counsel of the Open Source Initiative (OSI).
The license grants similar rights to the BSD, MIT, UoI/NCSA and Apache licenses – licenses allowing the software to be made proprietary – but was written to correct perceived problems with those licenses:
The AFL makes clear what software is being licensed by including a statement following the software's copyright notice;
The AFL includes a complete copyright grant to the software;
The AFL contains a complete patent grant to the software;
The AFL makes clear that no trademark rights are granted to the licensor's trademarks;
The AFL warrants that the licensor either owns the copyright or is distributing the software under a license;
The AFL is itself copyrighted, with the right granted to copy and distribute without modification.The Free Software Foundation consider all AFL versions through 3.0 as incompatible with the GNU GPL. though Eric S. Raymond (a co-founder of the OSI) contends that AFL 3.0 is GPL compatible. In late 2002, an OSI working draft considered it a "best practice" license. In mid-2006, however, the OSI's License Proliferation Committee found it "redundant with more popular licenses", specifically version 2 of the Apache Software License.Apple Public Source License
The Apple Public Source License (APSL) is the open-source and free software license under which Apple's Darwin operating system was released. A free and open-source software license was voluntarily adopted to further involve the community from which much of Darwin originated.
The first version of the Apple Public Source License was approved by the Open Source Initiative (OSI). Version 2.0, released July 29, 2003, is also approved as a free software license by the Free Software Foundation (FSF) which finds it acceptable for developers to work on projects that are already covered by this license. However, the FSF recommends that developers should not release new projects under this license, because the partial copyleft is not compatible with the GNU General Public License and allows linking with files released entirely as proprietary software. The license does require that if any derivatives of the original source are released externally, their source should be made available; the Free Software Foundation compares this requirement to a similar one in its own GNU Affero General Public License.Many software releases from Apple have now been relicensed under the more liberal Apache License, such as the Bonjour Zeroconf stack.Artistic License
The Artistic License (version 1.0) is a software license used for certain free and open-source software packages, most notably the standard implementation of the Perl programming language and most CPAN modules, which are dual-licensed under the Artistic License and the GNU General Public License (GPL).Beerware
Beerware is a somewhat tongue-in-cheek term for software released under a very relaxed license (beerware licensed software). It provides the end user with the right to use a particular program (or do anything else with the source code).Commercial software
Commercial software, or seldom payware, is computer software that is produced for sale or that serves commercial purposes. Commercial software can be proprietary software or free and open-source software.Common Public License
In computing, the Common Public License (CPL) is a free software / open-source software license published by IBM. The Free Software Foundation and Open Source Initiative have approved the license terms of the CPL.Comparison of free and open-source software licenses
This is a comparison of published free software licenses and open-source licenses. The comparison only covers software licenses with a linked article for details, approved by at least one expert group at the FSF, the OSI, the Debian project or the Fedora project. For a list of licenses not specifically intended for software, see List of free content licenses.Free software movement
The free software movement (FSM) or free/open-source software movement (FOSSM) or free/libre open-source software movement (FLOSSM) is a social movement with the goal of obtaining and guaranteeing certain freedoms for software users, namely the freedom to run the software, to study and change the software, and to redistribute copies with or without changes. Although drawing on traditions and philosophies among members of the 1970s hacker culture and academia, Richard Stallman formally founded the movement in 1983 by launching the GNU Project. Stallman later established the Free Software Foundation in 1985 to support the movement.ISC license
The ISC license is a permissive free software license published by the Internet Software Consortium, nowadays called Internet Systems Consortium (ISC). It is functionally equivalent to the simplified BSD and MIT licenses, but without language deemed unnecessary following the Berne Convention.Originally used for ISC software such as BIND and dig, it has become the preferred license for contributions to OpenBSD and the default license for npm packages. The ISC license is also used for Linux wireless drivers contributed by Qualcomm Atheros.List of free and open-source software organizations
The following are notable organizations devoted to the advocacy, legal aid, financial aid, technical aid, governance, etc. of free and open-source software (FOSS) as a whole, or of one or more specific FOSS projects. For projects that have their own foundation or are part of an umbrella organization, the primary goal is often to provide a mechanism for funding development of the software.
For the most part, these organizations are structured as nonprofit/charity organizations.
This list does not include companies that aim to make money from free and open-source software.List of free and open-source software packages
This is a list of free and open-source software 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; the GNU project in particular objects to their works being referred to as open-source. For more information about the philosophical background for open-source software, see free software movement and Open Source Initiative. However, nearly all software meeting the Free Software Definition also meets the Open Source Definition and vice versa. A small fraction of the software that meets either definition is listed here.
Some of the open-source applications are also the basis of commercial products, shown in the List of commercial open-source applications and services.Nvidia GameWorks
Nvidia GameWorks is a middleware software suite developed by Nvidia. The Visual FX, PhysX and Optix SDKs provide a wide range of enhancements pre-optimised for Nvidia GPUs. GameWorks is distributed in the form of compiled DLLs rather than traditional source code. The competing solution being in development by AMD is GPUOpen, which was announced to be free and open-source software under the MIT License. In March 2016 Nvidia made the source code of GameWorks available on GitHub.Open source
Open source is a term denoting that a product includes permission to use its source code, design documents, or content. It most commonly refers to the open-source model, in which open-source software or other products are released under an open-source license as part of the open-source-software movement. Use of the term originated with software, but has expanded beyond the software sector to cover other open content and forms of open collaboration.Python License
The Python License is a deprecated computer software license created by the Corporation for National Research Initiatives (CNRI). It was used for versions 1.6 and 2.0 of the Python programming language, both released in the year 2000.
The Python License is similar to the BSD License and, while it is a free software license, its wording in some versions meant that it was incompatible with the GNU General Public License (GPL) used by a great deal of free software including the Linux kernel. For this reason CNRI retired the license in 2001, and the license of current releases is owned by the Python Software Foundation License.Python Software Foundation License
The Python Software Foundation License (PSFL) is a BSD-style, permissive free software license which is compatible with the GNU General Public License (GPL). Its primary use is for distribution of the Python project software. Unlike the GPL the Python license is not a copyleft license, and allows modified versions to be distributed without source code. The PSFL is listed as approved on both FSF's approved licenses list, and OSI's approved licenses list.
In 2000, Python was briefly available under the Python License, which is incompatible with the GPL. The reason given for this incompatibility by Free Software Foundation was that "this Python license is governed by the laws of the 'State of Virginia', in the USA", which the GPL does not permit.Guido van Rossum, Python's creator, was awarded the 2001 Free Software Foundation Award for the Advancement of Free Software for changing the license to fix this incompatibility.Sleepycat License
The Sleepycat License (sometimes referred to as Berkeley database license where berkeley database is a library intended to provide a high performance embedded database for key/value data which is written in 'C' or the Sleepycat Public License) is a copyleft free software license used by Oracle Corporation for the open-source editions of Berkeley DB, Berkeley DB Java Edition and Berkeley DB XML embedded database products older than version 6.0.20. (Starting with version 6.0.20, the open-source editions are instead licensed under the GNU AGPL v3.)The Apache Software Foundation
The Apache Software Foundation (ASF) is an American non-profit corporation (classified as a 501(c)(3) organization in the United States) to support Apache software projects, including the Apache HTTP Server. The ASF was formed from the Apache Group and incorporated on March 25, 1999.The Apache Software Foundation is a decentralized open source community of developers. The software they produce is distributed under the terms of the Apache License and is free and open-source software (FOSS). The Apache projects are characterized by a collaborative, consensus-based development process and an open and pragmatic software license. Each project is managed by a self-selected team of technical experts who are active contributors to the project. The ASF is a meritocracy, implying that membership of the foundation is granted only to volunteers who have actively contributed to Apache projects. The ASF is considered a second generation open-source organization, in that commercial support is provided without the risk of platform lock-in.
Among the ASF's objectives are: to provide legal protection to volunteers working on Apache projects; to prevent the Apache brand name from being used by other organizations without permission.
The ASF also holds several ApacheCon conferences each year, highlighting Apache projects and related technology.The Open Source Definition
The Open Source Definition is a document published by the Open Source Initiative, to determine whether a software license can be labeled with the open-source certification mark.The definition was taken from the exact text of the Debian Free Software Guidelines, written and adapted primarily by Bruce Perens with input from the Debian developers on a private Debian mailing list. The document was created 9 months before the formation of the Open Source Initiative.Zlib License
The zlib license is a permissive free software license which defines the terms under which the zlib software library can be distributed. It is also used by many other free software packages. The libpng library uses a similar license sometimes referred interchangeably as the zlib/libpng license.
The zlib license has been approved by the Free Software Foundation (FSF) as a free software license, and by the Open Source Initiative (OSI) as an open source license. It is compatible with the GNU General Public License.
Free and open-source software