Software categories are groups of software. They allow software to be understood in terms of those categories. Instead of the particularities of each package. Different classification schemes consider different aspects of software.
Computer software can be put into categories based on common function, type, or field of use. There are three broad classifications:
The GNU Project categorizes software by copyright status: free software, open source software, public domain software, copylefted software, noncopylefted free software, lax permissive licensed software, GPL-covered software, the GNU operating system, GNU programs, GNU software, FSF-copyrighted GNU software, nonfree software, proprietary software, freeware, shareware, private software and commercial software.
Free software is software that comes with permission for anyone to use, copy and distribute, either verbatim or with modifications, either gratis or for a fee. In particular, this means that source code must be available. "If it's not source, it's not software." If a program is free, then it can potentially be included in a free operating system such as GNU, or free versions of the Linux system.
Free software in the sense of copyright license (and the GNU project) is a matter of freedom, not price. But proprietary software companies typically use the term "free software" to refer to price. Sometimes this means a binary copy can be obtained at no charge; sometimes this means a copy is bundled with a computer for sale at no additional charge.
Open source software is software with its source code made available under a certain license to its licensees. It can be used and disseminated at any point, the source code is open and can be modified as required. The one condition with this type of software is that when changes are made users should make these changes known to others. One of the key characteristics of open source software is that it is the shared intellectual property of all developers and users. The Linux operating system is one of the best known examples of a collection of open source software.
Copylefted software is free software whose distribution terms ensure that all copies of all versions carry more or less the same distribution terms. This means, for instance, that copyleft licenses generally disallow others to add additional requirements to the software (though a limited set of safe added requirements can be allowed) and require making source code available. This shields the program, and its modified versions, from some of the common ways of making a program proprietary. Some copyleft licenses block other means of turning software proprietary.
Copyleft is a general concept. Copylefting an actual program requires a specific set of distribution terms. Different copyleft licenses are usually “incompatible” due to varying terms, which makes it illegal to merge the code using one license with the code using the other license. If two pieces of software use the same license, they are generally mergeable.
Noncopylefted free software comes from the author with permission to redistribute and modify and to add license restrictions.
If a program is free but not copylefted, then some copies or modified versions may not be free. A software company can compile the program, with or without modifications, and distribute the executable file as a proprietary software product. The X Window System illustrates this approach. The X Consortium releases X11 with distribution terms that make it noncopylefted free software. If you wish, you can get a copy which has those distribution terms and is free. However, nonfree versions are available and workstations and PC graphics boards for which nonfree versions are the only ones that work. The developers of X11 made X11 nonfree for a while; they were able to do this because others had contributed their code under the same noncopyleft license.
Shareware is software that comes with permission to redistribute copies, but says that anyone who continues to use a copy is required to pay. Shareware is not free software, or even semi-free. For most shareware, source code is not available; thus, the program cannot be modified. Shareware does not come with permission to make a copy and install it without paying a license fee, including for nonprofit activity.
Like shareware, freeware is software available for download and distribution without any initial payment. Freeware never has an associated fee. Things like minor program updates and small games are commonly distributed as freeware. Though freeware is cost free, it is copyrighted, so other people can't market the software as their own.
This classification has seven major elements. They are: platform and management, education and reference, home and entertainment, content and communication, operations and professional, product manufacturing and service delivery, and line of business.
Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, not price: users—individually or in cooperation with computer programmers—are free to do what they want with their copies of a free software regardless of how much is paid to obtain the program. Computer programs are deemed free if they give users ultimate control over the software and, subsequently, over their devices.
The free software movement 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.
Freeware is software, most often proprietary, that is distributed at no monetary cost to the end user. There is no agreed-upon set of rights, license, or EULA that defines freeware unambiguously; every publisher defines its own rules for the freeware it offers. For instance, modification, redistribution by third parties, and reverse engineering without the author's permission are permitted by some publishers but prohibited by others. Unlike with free and open-source software, which are also often distributed free of charge, the source code for freeware is typically not made available. Freeware may be intended to benefit its producer by, for example, encouraging sales of a more capable version, as in the freemium and shareware business models.
GNU is an operating system and an extensive collection of computer software. GNU is composed wholly of free software, most of which is licensed under the GNU Project's own General Public License (GPL).
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 software without being required by the terms of a strong copyleft license to release the source code of their own components. However, any developer who modifies an LGPL-covered component is required to make their modified version available under the same LGPL license. For proprietary software, code under the LGPL is usually used in the form of a shared library, so that there is a clear separation between the proprietary and LGPL components. The LGPL is primarily used for software libraries, although it is also used by some stand-alone applications.
Shareware is a type of proprietary software which is initially provided free of charge to users, who are allowed and encouraged to make and share copies of the program. Shareware is often offered as a download from a website or on a compact disc included with a magazine. Shareware differs from freeware, which is software distributed at no cost to the user but without source code being made available; and open-source software, in which the source code is freely available for anyone to inspect and alter.
Viral license is an alternative name for copyleft licenses, especially the GPL, that allows derivative works only when permissions are preserved in modified versions of the work. Copyleft licenses include several common open-source and free content licenses, such as the GNU General Public License (GPL) and the Creative Commons Attribution-Sharealike license (CC-BY-SA).
The GNU Project is a free software, mass collaboration project that Richard Stallman announced on September 27, 1983. Its goal is to give computer users freedom and control in their use of their computers and computing devices by collaboratively developing and publishing software that gives everyone the rights to freely run the software, copy and distribute it, study it, and modify it. GNU software grants these rights in its 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.
Software copyright is the application of copyright law to machine-readable software. While many of the legal principles and policy debates concerning software copyright have close parallels in other domains of copyright law, there are a number of distinctive issues that arise with software. This article primarily focuses on topics particular to software.
Commercial software, or seldom payware, is a computer software that is produced for sale or that serves commercial purposes. Commercial software can be proprietary software or free and open-source software.
A software license is a legal instrument governing the use or redistribution of software. Under United States copyright law, all software is copyright protected, in both source code and object code forms, unless that software was developed by the United States Government, in which case it cannot be copyrighted. Authors of copyrighted software can donate their software to the public domain, in which case it is also not covered by copyright and, as a result, cannot be licensed.
Free/open-source software – the source availability model used by free and open-source software (FOSS) – and closed source are two approaches to the distribution of software.
A permissive software license, sometimes also called BSD-like or BSD-style license, is a free-software license with minimal requirements about how the software can be redistributed. Examples include the GNU All-permissive License, MIT License, BSD licenses, Apple Public Source License and Apache license. As of 2016, the most popular free-software license is the permissive MIT license. Permissive licenses do not try to guarantee that future versions of the software will remain free and publicly available, in contrast to copyleft licenses, which have reciprocity requirements which try to enforce this. Software under a permissive license can later be made proprietary.
The Ruby License is a Free and Open Source license applied to the Ruby programming language and also available to be used in other projects. It is approved by the Free Software Foundation although it has not been approved Open Source by the Open Source Initiative.
License compatibility is a legal framework that allows for pieces of software with different software licenses to be distributed together. The need for such a framework arises because the different licenses can contain contradictory requirements, rendering it impossible to legally combine source code from separately-licensed software in order to create and publish a new program. Proprietary licenses are generally program-specific and incompatible; authors must negotiate to combine code. Copyleft licenses are deliberately incompatible with proprietary licenses, in order to prevent copyleft software from being re-licensed under a proprietary license, turning it into proprietary software. Many copyleft licenses explicitly allow relicensing under some other copyleft licenses. Permissive licenses are compatible with everything, including proprietary licenses; there is thus no guarantee that all derived works will remain under a permissive license.
A free-software license is a notice that grants the recipient of a piece of software extensive rights to modify and redistribute that software. These actions are usually prohibited by copyright law, but the rights-holder of a piece of software can remove these restrictions by accompanying the software with a software license which grants the recipient these rights. Software using such a license is free software as conferred by the copyright holder. Free-software licenses are applied to software in source code and also binary object-code form, as the copyright law recognizes both forms.
Copyleft, distinguished from copyright, is the practice of offering people the right to freely distribute copies and modified versions of a work with the stipulation that the same rights be preserved in derivative works created later. Copyleft software licenses are considered protective or reciprocal, as contrasted with permissive free-software licenses.
Proprietary software, also known as closed-source software, is non-free computer software for which the software's publisher or another person retains intellectual property rights—usually copyright of the source code, but sometimes patent rights.
The GNU General Public License is a series of widely used free software licenses that guarantee end users the freedom to run, study, share, and modify the software. The licenses were originally written by Richard Stallman, former head of the Free Software Foundation (FSF), for the GNU Project, and grant the recipients of a computer program the rights of the Free Software Definition. The GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. This is in distinction to permissive software licenses, of which the BSD licenses and the MIT License are widely used, less restrictive examples. GPL was the first copyleft license for general use.
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