Software: Difference between revisions
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[[File:Operating system placement (software).svg|thumb|upright|A diagram showing how the [[User (computing)|user]] interacts with [[application software]] on a typical [[desktop computer]]. The application software layer interfaces with the [[operating system]], which in turn communicates with the [[computer hardware|hardware]]. The arrows indicate information flow.]] |
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[[File:Credit-cards.jpg|thumb|[[Credit card]]s are one of many everyday technologies that are dependent on software.{{sfn|Kitchin |Dodge|2011|p=5}}]] |
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'''Software''' is a collection of [[computer program|program]]s and [[data (computing)|data]] that tell a computer how to perform specific tasks. Software often includes associated [[software documentation]].<ref name="ISO 2020">{{cite web |date=2020-09-03 |title=ISO/IEC 2382:2015 |url=https://www.iso.org/cms/render/live/en/sites/isoorg/contents/data/standard/06/35/63598.html |access-date=2022-05-26 |website=ISO |language=en-US |quote=[Software includes] all or part of the programs, procedures, rules, and associated documentation of an information processing system. |archive-date=16 March 2023 |archive-url=https://web.archive.org/web/20230316023234/https://www.iso.org/standard/63598.html |url-status=live }}</ref> This is in contrast to [[computer hardware|hardware]], from which the system is built and which actually performs the work. |
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'''Software''' is defined narrowly as unambiguous instructions that can be transformed into a form [[execution (computing)|executable]] on [[computer hardware]], or more broadly including supporting concepts, tools and methods needed to make the computer system operational. |
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Building off of previous innovations in [[mathematics]] and technology, software was created for the programmable [[digital computers]] that emerged in the late 1940s and was necessary to realize their usefulness. The first software was tied closely to the underlying [[computer hardware]], but over time, the lower [[abstraction layer|layers]] of the system have become more standardized, and software has become increasingly [[portability (computing)|portability]] between different systems and abstracted from the underlying [[machine code]]. [[Operating systems]] manage the hardware resources and mediate between different [[application software|applications]] that accomplish tasks for the user. Programming languages are the format in which software is written, and must be both human-readable and capable of being translated into unambiguous instructions for computer hardware. [[Compiler]]s or [[Interpreter (computing)|interpreter]]s are needed to link a program with other code that it relies on and convert the software into [[machine code]] that can be [[execution (computing)|executed]] on the hardware. Programs are combined with each other and with external input to be capable of accomplishing a complex task. |
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At the [[low-level programming language|lowest programming level]], [[executable code]] consists of [[machine code|machine language]] instructions supported by an individual [[processor (computing)|processor]]—typically a [[central processing unit]] (CPU) or a [[graphics processing unit]] (GPU). Machine language consists of groups of [[Binary number|binary values]] signifying [[instruction set architecture|processor instructions]] that change the state of the computer from its preceding state. For example, an instruction may change the value stored in a particular storage location in the computer—an effect that is not directly observable to the user. An instruction [[system call|may also invoke]] one of many [[input/output|input or output operations]], for example, displaying some text on a computer screen, causing state changes that should be visible to the [[user (computing)|user]]. The processor [[instruction cycle|executes]] the instructions in the order they are provided, unless it is instructed to [[branch instruction|"jump" to a different instruction]] or is [[interrupt]]ed by the operating system. {{As of|2024}}, most [[personal computer]]s, [[smartphone]] devices, and [[server (computing)|servers]] have [[multi-core processor|processors with multiple execution units]], or [[multiprocessing|multiple processors performing computation]] together, so computing has become a much more [[concurrent computing|concurrent]] activity than in the past. |
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[[Computer programming|Programming]] and [[Software maintenance|maintaining]] the [[source code]] is the central step of [[software development]], but it also includes conceiving the project, evaluating its feasibility, analyzing the business requirements, [[software design]], and [[software release life cycle|release]]. [[Software quality assurance]], including [[code review]] and [[software testing|testing]], is an essential part of the process as delivering quality code lowers the cost of [[software reliability|reliability]] failures, [[cyberattack]]s enabled by [[vulnerability (computing)|security vulnerabilities]], and [[maintainability|maintenance cost]]. Maintenance typically consumes 75 percent or more of the software's lifetime engineering budget. Source code [[software copyright|is protected]] by [[copyright law]] that vests the owner with the exclusive right to copy the code. Software has become ubiquitous in [[everyday life]] in [[developed countries]]. In many cases, software augments the functionality of pre-existing technologies, but it has also enabled the creation of entirely new technologies such as [[the Internet]], [[video games]], [[social media]], [[mobile phones]], and [[GPS]]. |
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The majority of software is written in [[high-level programming language]]s for example [[Python (programming language)|Python]], [[JavaScript]], [[Visual Basic]], [[Delphi (software)|Delphi]], [[Perl]], [[PHP]], [[ECMAScript]], [[Ruby (programming language)|Ruby]], [[C Sharp (programming language)|C#]], and [[Java (programming language)|Java]]. They are easier and more efficient for programmers because they are closer to [[natural language]]s than machine languages.<ref>{{cite web |title=Compiler construction |url=http://www.cs.uu.nl/education/vak.php?vak=INFOMCCO |url-status= |archive-url=https://web.archive.org/web/20131102143144/http://www.cs.uu.nl/education/vak.php?vak=INFOMCCO |archive-date=2 November 2013 |website=cs.uu.nl |df=dmy-all}}</ref> High-level languages are translated into machine language using a [[compiler]], an [[Interpreter (computing)|interpreter]], or a combination of the two. Software may also be written in a low-level [[assembly language]], for example [[C (programming language)|C]], [[C++]], [[Assembly language|Assembly]], and [[Fortran]]. Assembly languages have a strong correspondence to the computer's machine language instructions and are translated into machine language using an assembler. |
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==Definition== |
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Software can be defined more narrowly as the instructions executed by the [[computer hardware]], or more broadly including other concepts, tools, and methods needed to make an [[execution (computing)|executable]] system on [[computer hardware]], such as design documents, specifications, and testing suites.{{sfn|Osterweil|2013|p=61}}{{sfn|Tracy|2021|p=2}} An individual [[computer program|program]] or [[source code]] file consists of unambiguous instructions and [[algorithm]]s. Programs are combined with each other and with external input to be capable of accomplishing a complex task.{{sfn|Kitchin |Dodge|2011|pp=3, 24}}{{sfn|Tracy|2021|p=2}} Tools such as [[compiler]]s, [[Assembly language|assembler]]s, [[flowchart]]s, design tools, simulators, and [[architectural diagram]]s—some of which are also software—are essential to the design and execution of most computing systems.{{sfn|Tracy|2021|p=2}} Although software is [[Intangible asset|intangible]],{{sfn|Tracy|2021|p=3}}{{sfn|Kitchin |Dodge|2011|p=24}} software makes instructions for [[computer hardware]] to produce visible and tangible effects.{{sfn|Kitchin |Dodge|2011|pp=3-4}} |
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==History== |
==History== |
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{{Main|History of software}} |
{{Main|History of software}} |
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[[File:07R01.jpg|thumb|[[07R01]], an [[integrated circuit]] by [[Motorola]]. Integrated circuits were an essential enabling invention allowing the creation of software.{{sfn|Jones|2014|pp=19, 22}}]] |
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An [[algorithm]] for what would have been the first piece of software was written by [[Ada Lovelace]] in the 19th century, for the planned [[Analytical Engine]].{{Sfn|Evans|2018|p=21}} She created [[mathematical proof|proofs]] to show how the engine would calculate [[Bernoulli number]]s.{{Sfn|Evans|2018|p=21}} Because of the proofs and the algorithm, she is considered the first computer programmer.<ref name="Annals of the History of Computing">{{cite journal|last1=Fuegi|first1=J.|last2=Francis|first2=J.|date=2003|title=Lovelace & Babbage and the creation of the 1843 'notes'|journal=Annals of the History of Computing|volume=25|issue=4|pages=16–26|doi=10.1109/MAHC.2003.1253887|s2cid=40077111|url=https://pdfs.semanticscholar.org/81bb/f32d2642a7a8c6b0a867379a4e9e99d872bc.pdf|archive-url=https://web.archive.org/web/20200215003909/https://pdfs.semanticscholar.org/81bb/f32d2642a7a8c6b0a867379a4e9e99d872bc.pdf|url-status=dead|archive-date=2020-02-15}}</ref><ref name="Lovelace Google">{{Cite news |last= |first= |date=December 10, 2012 |title=Ada Lovelace honoured by Google doodle |language=en-US |newspaper=The Guardian |url=https://www.theguardian.com/technology/2012/dec/10/ada-lovelace-honoured-google-doodle |url-status=live |access-date=25 November 2018 |archive-url=https://web.archive.org/web/20181225024306/https://www.theguardian.com/technology/2012/dec/10/ada-lovelace-honoured-google-doodle |archive-date=Dec 25, 2018}}</ref> |
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<!-- [[File:IBM Electronic Data Processing Machine - GPN-2000-001881.jpg|thumb|Two people using an [[IBM 704]] [[mainframe]]—the first hardware to support [[floating-point arithmetic]]—in 1957. [[Fortran]] was designed for this machine.{{sfn|Sebesta|2012|pp=42–44}}{{sfn|Gabbrielli|Martini|2023|p=524}}]] --> |
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A host of earlier inventions were necessary for the creation of software, including [[mathematics]]—especially [[binary number|binary]] and [[decimal]] number systems, and [[zero]]—[[alphabet]]s, [[writing]], [[mechanical calculator]]s,{{sfn|Jones|2014|pp=9, 21}} [[boolean algebra]], [[transistor]]s, [[integrated circuit]]s, and [[plastics]].{{sfn|Jones|2014|p=19}} Software could not exist without [[digital computers]], as it was created specifically for these devices and was necessary to realize their usefulness.{{sfn|Jones|2014|p=22}} |
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The first programmable computers, which appeared at the end of the 1940s,{{sfn|Gabbrielli|Martini|2023|p=519}} were programmed in [[machine language]] (simple instructions that could be directly executed by the processor). Machine language was difficult to debug and was not [[portability (computing)|portable]] between different computer systems.{{sfn|Gabbrielli|Martini|2023|pp=520–521}} Initially, hardware resources were scarce and expensive, while [[human resources]] were cheaper.{{sfn|Gabbrielli|Martini|2023|p=522}} As programs grew more complex, [[programmer productivity]] became a bottleneck. This led to the introduction of [[high-level programming language]]s in the mid-1950s. These languages [[abstraction (computing)|abstracted]] away the details of the hardware, instead being designed to express algorithms that could be understood more easily by humans.{{sfn|Gabbrielli|Martini|2023|p=521}}{{sfn|Tracy|2021|p=1}} As instructions distinct from the underlying [[computer hardware]], software is therefore relatively recent, dating to these early high-level [[programming languages]] such as [[Fortran]], [[Lisp (programming language)|Lisp]], and [[Cobol]].{{sfn|Tracy|2021|p=1}} The first use of the word ''software'' is credited to mathematician [[John Wilder Tukey]] in 1958.{{sfn|Tracy|2021|p=2}} |
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The first theory about software, prior to the creation of computers as we know them today, was proposed by [[Alan Turing]] in his 1936 essay, ''On Computable Numbers, with an Application to the [[Entscheidungsproblem]]'' (decision problem).<ref name="Turing_1936">{{cite journal|last1=Turing|first1=Alan Mathison|date=1936|title=On Computable Numbers, with an Application to the Entscheidungsproblem|journal=Journal of Mathematics|volume=58|pages=230–265|url=https://www.wolframscience.com/prizes/tm23/images/Turing.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://www.wolframscience.com/prizes/tm23/images/Turing.pdf |archive-date=2022-10-09 |url-status=live|access-date=2022-08-28}}</ref> This eventually led to the creation of the academic fields of computer science and software engineering; both fields study software and its creation.<ref>{{Cite web |title=What's the Difference Between Computer Science and Software Engineering? |url=https://www.evidyalam.com/2023/10/computer-science-vs-software-engineering.html |access-date=2023-10-24 |website=eVidyalam |language=en}}</ref> Computer science is the theoretical study of computer and software (Turing's essay is an example of computer science), whereas software engineering is the application of engineering principles to development of software.<ref>{{Cite journal |last=Lorge Parnas |first=David |date=1984-11-01 |title=Software Engineering Principles |url=https://doi.org/10.1080/03155986.1984.11731932 |journal=INFOR: Information Systems and Operational Research |volume=22 |issue=4 |pages=303–316 |doi=10.1080/03155986.1984.11731932 |issn=0315-5986}}</ref> |
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In 2000, Fred Shapiro, a librarian at the Yale Law School, published a letter revealing that [[John Wilder Tukey]]'s 1958 paper "The Teaching of Concrete Mathematics"<ref name="Tukey_1958"/><ref name="Beebe_2017"/> contained the earliest known usage of the term "software" found in a search of [[JSTOR]]'s electronic archives, predating the [[OED|''Oxford English Dictionary'']]'s citation by two years.<ref name="Shapiro_2000"/> This led many to credit Tukey with coining the term, particularly in obituaries published that same year,<ref name="Leonhardt_2000"/> although Tukey never claimed credit for any such coinage. In 1995, Paul Niquette claimed he had originally coined the term in October 1953, although he could not find any documents supporting his claim.<ref name="Niquette_2006"/> The earliest known publication of the term "software" in an engineering context was in August 1953 by Richard R. Carhart, in a [[Rand Corporation]] Research Memorandum.<ref name="Carhart_1953"/> |
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The first software was tied closely to the underlying hardware and consequently was not [[Portability (computer science)|portable]] to other systems. As it has evolved, newer software can be built and run on a wide variety of platforms. Much of the increase in portability can be attributed to standardization of lower-level aspects of the system, such as [[Computer network|networking]], [[operating system]]s, and [[database]]s. Because there are only a relatively few operating systems, [[Transmission Control Protocol|TCP]] and [[Internet Protocol|IP]] are used for virtually all networking, and [[SQL]] is used for many database queries, [[application software]] can run more easily over a wide variety of hardware.{{sfn|Tracy|2021|p=249}} Increasing the number of layers of [[abstraction]] in the system is a related development: both in programming languages where it enables better structure and increased [[modularity]], as well as enabling [[virtualization]] of system resources. As a result of the increase in stability and abstraction, software has become increasingly complex and can solve more problems.{{sfn|Tracy|2021|p=250}} Both industry and [[academia]] have had a strong influence on the development of different aspects of software.{{sfn|Tracy|2021|pp=250-251}} |
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==Types== |
==Types== |
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{{See also|Software categories}} |
{{See also|Software categories}} |
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[[File:Cube in Blender Editor.jpg|thumb|250px|[[Blender (software)|Blender]], a [[free software]] program]] |
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[[File:Operating system placement (software).svg|thumb|upright|A diagram showing how the [[User (computing)|user]] interacts with [[application software]] on a typical [[desktop computer]]. The application software layer interfaces with the [[operating system]], which in turn communicates with the [[computer hardware|hardware]]. The arrows indicate information flow.]] |
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On virtually all computer platforms, software can be grouped into a few broad categories. |
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There are two main types of software: |
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* [[Operating system]]s are "the [[abstraction layer|layer of software]] that manages a computer's resources for its users and their [[Application software|application]]s".{{sfn|Anderson|Dahlin|2014|p=6}} There are three main purposes that an operating system fulfills:{{sfn|Anderson|Dahlin|2014|p=7}} |
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**Allocating resources between different applications, deciding when they will receive [[central processing unit]] (CPU) time or space in [[computer memory|memory]].{{sfn|Anderson|Dahlin|2014|p=7}} |
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**Providing an interface that abstracts the details of accessing [[Computer hardware|hardware]] details (like physical memory) to make things easier for programmers.{{sfn|Anderson|Dahlin|2014|p=7}}{{sfn|Tanenbaum|Bos|2023|p=5}} |
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**Offering common services, such as an interface for accessing network and disk devices. This enables an application to be run on different hardware without needing to be rewritten.{{sfn|Anderson|Dahlin|2014|pp=7, 9, 13}} |
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* [[Application software]] runs on top of the operating system and uses the computer's resources to perform a task.{{sfn|Anderson|Dahlin|2014|pp=6-7}} There are many different types of application software because the range of tasks that can be performed with modern computers is so large.{{sfn|Jones|2014|p=121}} Applications account for most software{{sfn|Tracy|2021|p=66}} and require the [[Operating environment|environment]] provided by an operating system, and often other applications, in order to function.{{sfn|Tracy|2021|p=72}} |
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[[File:Comparison of on-premise, IaaS, PaaS, and SaaS.png|thumb|Comparison of on-premise hardware and software, [[infrastructure as a service]] (IaaS), [[platform as a service]] (PaaS), and [[software as a service]] (SaaS)|upright=2.4|center]] |
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===Purpose, or domain of use=== |
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Software can also be categorized by how it is [[software deployment|deployed]]. Traditional applications are purchased with a perpetual [[software license|license]] for a specific version of the software, downloaded, and run on hardware belonging to the purchaser.{{sfn|O'Regan|2022|p=386}} The rise of [[the Internet]] and [[cloud computing]] enabled a new model, [[software as a service]] (SaaS),{{sfn|Campbell-Kelly|Garcia-Swartz|2015|pp=156-157}} in which the provider hosts the software (usually built on top of rented [[infrastructure as a service|infrastructure]] or [[platform as a service|platform]]s){{sfn|Rosati |Lynn|2020|p=23}} and provides the use of the software to customers, often in exchange for a [[subscription fee]].{{sfn|O'Regan|2022|p=386}} By 2023, SaaS products—which are usually delivered via a [[web application]]—had become the primary method that companies deliver applications.{{sfn|Watt|2023|p=4}} |
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Based on the goal, computer software can be divided into: |
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* '''[[Application software]]''' uses the computer system to perform special functions beyond the basic operation of the computer itself. There are many different types of application software because the range of tasks that can be performed with a modern computer is so large—see [[list of software]]. |
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* '''[[System software]]''' manages hardware behaviour, as to provide basic functionalities that are required by users, or for other software to run properly, if at all. System software is also designed to provide a platform for running application software,<ref>{{cite web|url=http://home.olemiss.edu/~misbook/sfsysfm.htm|title=System Software|publisher=The University of Mississippi|archive-url=https://web.archive.org/web/20010530092843/http://home.olemiss.edu/~misbook/sfsysfm.htm|archive-date=30 May 2001|url-status=dead|df=dmy-all}}</ref> and it includes the following: |
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** '''[[Operating system]]s''' are essential collections of software that manage resources and provide common services for other software that runs "on top" of them. [[Supervisory program]]s, [[boot loader]]s, [[shell (computing)|shells]] and [[window system]]s are core parts of operating systems. In practice, an operating system comes bundled with additional software (including application software) so that a user can potentially do some work with a computer that only has one operating system. |
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** '''[[Device driver]]s''' operate or control a particular type of device that is attached to a computer. Each device needs at least one corresponding device driver; because a computer typically has at minimum at least one input device and at least one output device, a computer typically needs more than one device driver. |
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** '''[[Software utility|Utilities]]''' are computer programs designed to assist users in the maintenance and care of their computers. |
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* '''[[Malicious software]]''', or '''malware''', is software that is developed to harm or disrupt computers. Malware is closely associated with computer-related crimes, though some malicious programs may have been designed as [[practical joke]]s. |
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==Software development and maintenance== |
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===Nature or domain of execution=== |
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[[File:Traditional software development life cycle diagram.png|thumb|upright=2.5|center|Diagram for a traditional [[software development life cycle]] from 1988. The numbers represent the typical cost of each phase.]] |
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* [[Desktop application]]s such as [[web browser]]s and [[Microsoft Office]] and [[LibreOffice]] and [[WordPerfect]], as well as [[smartphone]] and [[Tablet computer|tablet]] applications (called "[[mobile app|apps]]").<ref>{{cite web |date=2011-01-08 |title='App' voted 2010 word of the year by the American Dialect Society (UPDATED) |url=http://www.americandialect.org/app-voted-2010-word-of-the-year-by-the-american-dialect-society-updated |url-status=live |archive-url=https://web.archive.org/web/20150905032056/http://www.americandialect.org/app-voted-2010-word-of-the-year-by-the-american-dialect-society-updated |archive-date=2015-09-05 |access-date=2012-01-28 |publisher=American Dialect Society}}</ref> |
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* [[JavaScript]] scripts are pieces of software traditionally embedded in [[web page]]s that are run directly inside the web browser when a web page is loaded without the need for a web browser plugin. Software written in other programming languages can also be run within the web browser if the software is either translated into JavaScript, or if a web browser plugin that supports that language is installed; the most common example of the latter is [[ActionScript]] scripts, which are supported by the [[Adobe Flash]] plugin.<ref>{{Cite web |date=2007-09-16 |title=Press Release |url=https://web.archive.org/web/20070916144913/https://wp.netscape.com/newsref/pr/newsrelease67.html |access-date=2024-03-17 |website=web.archive.org}}</ref> |
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* [[Server software]], including: |
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** [[Web application]]s, which usually run on the [[web server]] and output dynamically generated web pages to web browsers, using e.g. [[PHP]], [[Java (programming language)|Java]], [[ASP.NET]], or even [[Node.js|JavaScript that runs on the server]]. In modern times these commonly include some JavaScript to be run in the web browser as well, in which case they typically run partly on the server, partly in the web browser.<ref name="deployedstats">{{cite web |title=Usage Statistics of JavaScript as Client-side Programming Language on Websites |url=https://w3techs.com/technologies/details/cp-javascript |access-date=2024-02-27 |website=W3Techs}}</ref> |
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* [[Plug-in (computing)|Plugins]] and extensions are software that extends or modifies the functionality of another piece of software, and require that software be used in order to function.<ref>{{Cite web |title=What is a Plugin? |url=https://www.computerhope.com/jargon/p/plugin.htm |url-status=live |access-date=2022-01-26 |website=Computer Hope |date=June 6, 2021 |language=en-US |archive-date=26 January 2022 |archive-url=https://web.archive.org/web/20220126171421/https://www.computerhope.com/jargon/p/plugin.htm }}</ref> |
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* [[Embedded software]] resides as [[firmware]] within [[embedded system]]s, devices dedicated to a single use or a few uses such as [[car]]s and [[television]]s (although some embedded devices such as wireless chipsets can ''themselves'' be part of an ordinary, non-embedded computer system such as a PC or smartphone).<ref>{{cite web|title=Embedded Software—Technologies and Trends|url=http://www.computer.org/csdl/mags/so/2009/03/mso2009030014.html|publisher=IEEE Computer Society|date=May–June 2009|access-date=6 November 2013|url-status=live|archive-url=https://web.archive.org/web/20131028045823/http://www.computer.org/csdl/mags/so/2009/03/mso2009030014.html|archive-date=28 October 2013|df=dmy-all}}</ref> In the embedded system context there is sometimes no clear distinction between the system software and the application software. However, some embedded systems run [[embedded operating system]]s, and these systems do retain the distinction between system software and application software (although typically there will only be one, fixed application which is always run).<ref>{{cite web |title=Tessel 2... Leverage all the libraries of Node.JS to create useful devices in minutes with Tessel. |url=https://tessel.io/ |url-status=live |archive-url=https://web.archive.org/web/20210526212559/https://tessel.io/ |archive-date=2021-05-26 |access-date=2021-05-08 |website=tessel.io}}</ref><ref>{{cite web |title=Node.js Raspberry Pi GPIO Introduction |url=https://www.w3schools.com/nodejs/nodejs_raspberrypi_gpio_intro.asp |url-status=live |archive-url=https://web.archive.org/web/20210813192938/https://www.w3schools.com/nodejs/nodejs_raspberrypi_gpio_intro.asp |archive-date=2021-08-13 |access-date=2020-05-03 |website=w3schools.com}}</ref><ref>{{cite web |title=Espruino – JavaScript for Microcontrollers |url=https://www.espruino.com/ |url-status=live |archive-url=https://web.archive.org/web/20200501010722/https://www.espruino.com/ |archive-date=2020-05-01 |access-date=2020-05-03 |website=espruino.com}}</ref> |
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* [[Microcode]] is a special, relatively obscure type of embedded software which tells the processor ''itself'' how to execute machine code, so it is actually a lower level than machine code.<ref>{{cite journal|last1=Landskov|first1=D.|last2=Davidson|first2=S.|last3=Shriver|first3=B.|last4=Mallett|first4=P.W.|date=1980|title=Local microcode compaction techniques|journal=ACM Computing Surveys|volume=12|issue=3|pages=261–294|doi=10.1145/356819.356822 |s2cid=16238043 }}</ref> It is typically proprietary to the processor manufacturer, and any necessary correctional microcode software updates are supplied by them to users (which is much cheaper than shipping replacement processor hardware). Thus an ordinary programmer would not expect to ever have to deal with it.{{Citation needed|date=September 2021}} |
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Software companies aim to deliver a high-quality product on time and under budget. A challenge is that [[software development effort estimation]] is often inaccurate.{{sfn|O'Regan|2022|p=7}} [[Software development]] begins by conceiving the project, evaluating its feasibility, analyzing the business requirements, and making a [[software design]].{{sfn|O'Regan|2022|p=5}}{{sfn|Dooley|2017|p=1}} Most software projects speed up their development by [[software reuse|reusing]] or incorporating existing software, either in the form of [[commercial off-the-shelf]] (COTS) or [[open-source software]].{{sfn|O'Regan|2022|pp=18, 110-111}}{{sfn|Tracy|2021|pp=43, 76}} [[Software quality assurance]] is typically a combination of manual [[code review]] by other engineers{{sfn|O'Regan|2022|pp=117-118}} and automated [[software testing]]. Due to time constraints, testing cannot cover all aspects of the software's intended functionality, so developers often focus on the most critical functionality.{{sfn|O'Regan|2022|p=54}} [[Formal method]]s are used in some safety-critical systems to prove the correctness of code,{{sfn|O'Regan|2022|p=267}} while [[user acceptance testing]] helps to ensure that the product meets customer expectations.{{sfn|O'Regan|2022|p=20}} There are a variety of [[software development methodologies]], which vary to completing all steps in order to concurrent and iterative models.{{sfn|O'Regan|2022|p=9}} Software development is driven by [[software requirements|requirements]] taken from prospective users, as opposed to maintenance that is driven by events such as a change request.{{sfn|Tripathy |Naik|2014|p=26}} |
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===Programming tools=== |
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{{Main|Programming tool}} |
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Programming tools are also software in the form of programs or applications that [[software developer|developer]]s use to create, [[Debugging|debug]], [[Software maintenance|maintain]], or otherwise [[Technical support|support]] software.<ref>{{Cite web |title=What is a Programming Tool? - Definition from Techopedia |url=http://www.techopedia.com/definition/8996/programming-tool |url-status=live |access-date=2022-01-26 |website=Techopedia.com |date=2 July 2020 |language=en-US |archive-date=26 January 2022 |archive-url=https://web.archive.org/web/20220126183105/https://www.techopedia.com/definition/8996/programming-tool }}</ref>{{better source needed|date=June 2022}} |
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Frequently, software is [[software release life cycle|released]] in an incomplete state when the development team runs out of time or funding.{{sfn |Reifer|2012|p=22}} Despite [[software testing|testing]] and [[Software quality assurance|quality assurance]], virtually all software contains [[software bug|bugs]] where the system does not work as intended. Post-release [[software maintenance]] is necessary to remediate these bugs when they are found and keep the software working as its the environment changes over time.{{sfn|Tripathy |Naik|2014|pp=4, 27}} New features are often added after release. Over time, the level of maintenance becomes increasingly restricted before being cut off entirely when the product is withdrawn from the market.{{sfn|Tripathy |Naik|2014|p=89}} As software [[software aging|ages]], it becomes known as [[legacy software]] and can remain in use for decades, even if there is no one left who knows how to fix it.{{sfn|Tracy|2021|p=3}} Over the lifetime of the product, software maintenance is estimated to comprise 75 percent or more of the total development cost.{{sfn|Varga|2018|p=6}}{{sfn|Ulziit ''et al.''|2015|p=764}} |
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Software is written in one or more programming languages; there are many [[programming language]]s in existence, and each has at least one implementation, each of which consists of its own set of programming tools. These tools may be relatively self-contained programs such as [[compiler]]s, [[debugger]]s, [[interpreter (computing)|interpreters]], [[linker (computing)|linkers]], and [[text editor]]s, that can be combined to accomplish a task; or they may form an [[integrated development environment]] (IDE), which combines much or all of the functionality of such self-contained tools.<ref>{{Cite book |url=https://link.springer.com/book/10.1007/978-3-031-11806-7 |title=Programming Language Design and Implementation |language=en |doi=10.1007/978-3-031-11806-7}}</ref> IDEs may do this by either invoking the relevant individual tools or by re-implementing their functionality in a new way.{{Citation needed|date=September 2021}} An IDE can make it easier to do specific tasks, such as searching for files in a particular project.<ref>{{Cite web |title=What is an IDE? - Integrated Development Environment Explained - AWS |url=https://aws.amazon.com/what-is/ide/ |access-date=2024-04-25 |website=Amazon Web Services, Inc. |language=en-US}}</ref> Many programming language implementations provide the option of using both individual tools or an IDE.{{Citation needed|date=September 2021}} |
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Completing a software project involves various forms of expertise, not just in [[software programmer]]s but also testing, documentation writing, [[Software project management|project management]], [[graphic design]], [[user experience]], user support, [[marketing]], and fundraising.{{sfn|Tucker |Morelli |de Silva |2011|p=7}}{{sfn|Stull|2018|pp=24-25}}{{sfn|Dooley|2017|p=1}} |
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==Topics== |
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==Quality and security== |
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===Architecture=== |
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{{ |
{{main article|Software quality|Computer security}} |
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[[Software quality]] is defined as meeting the stated requirements as well as customer expectations.{{sfn|Galin|2018|p=3}} Quality is an overarching term that can refer to a code's correct and efficient behavior, its reusability and [[porting|portability]], or the ease of modification.{{sfn|Galin|2018|p=26}} It is usually more cost-effective to build quality into the product from the beginning rather than try to add it later in the development process.{{sfn|O'Regan|2022|pp=68, 117}} Higher quality code will reduce lifetime cost to both suppliers and customers as it is more reliable and [[maintainability|easier to maintain]].{{sfn|O'Regan|2022|pp=3, 268}}{{sfn|Varga|2018|p=12}} Software failures in [[safety-critical system]]s can be very serious including death.{{sfn|O'Regan|2022|pp=3, 268}} By some estimates, the cost of poor quality software can be as high as 20 to 40 percent of sales.{{sfn|O'Regan|2022|p=119}} Despite developers' goal of delivering a product that works entirely as intended, virtually all software contains bugs.{{sfn|Ablon|Bogart|2017|p=1}} |
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People who use modern general purpose computers (as opposed to [[embedded system]]s, [[analog computer]]s and [[supercomputer]]s) usually see three layers of software performing a variety of tasks: platform, application, and user software.{{Citation needed|date=September 2021}} |
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* '''Platform software''': The [[computing platform|platform]] includes the [[firmware]], [[device driver]]s, an [[operating system]], and typically a [[graphical user interface]] which, in total, allow a user to interact with the computer and its [[peripheral]]s (associated equipment). Platform software often comes bundled with the computer. On a [[Personal computer|PC]] one will usually have the ability to change the platform software. |
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* '''Application software''': [[Application software]] is what most people think of when they think of software.{{Citation needed|date=September 2021}} Typical examples include office suites and [[video game]]s. Application software is often purchased separately from computer hardware. Sometimes applications are bundled with the computer, but that does not change the fact that they run as independent applications. Applications are usually independent programs from the operating system, though they are often tailored for specific platforms. Most users think of compilers, databases, and other "system software" as applications.<ref>{{Cite web |last=Indeed Editorial Team |date=December 28, 2022 |title=What Is Application Software? Definition, Types and FAQs |url=https://www.indeed.com/career-advice/career-development/what-is-application-software |website=Indeed}}</ref> |
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* '''User-written software''': [[End-user development]] tailors systems to meet users' specific needs. User software includes spreadsheet templates and [[word processor]] templates.{{Citation needed|date=September 2021}} Even email filters are a kind of user software. Users create this software themselves and often overlook how important it is.{{Citation needed|date=September 2021}} Depending on how competently the user-written software has been integrated into default application packages, many users may not be aware of the distinction between the original packages, and what has been added by co-workers.{{Citation needed|date=September 2021}} |
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The rise of the Internet also greatly increased the need for [[computer security]] as it enabled malicious actors to conduct [[cyberattack]]s remotely.{{sfn|Campbell-Kelly|Garcia-Swartz|2015|p=164}}{{sfn|O'Regan|2022|p=266}} If a bug creates a security risk, it is called a [[vulnerability (computing)|vulnerability]].{{sfn|Ablon|Bogart|2017|p=2}}{{sfn|Daswani |Elbayadi|2021|p=25}} [[Software patch]]es are often released to fix identified vulnerabilities, but those that remain unknown ([[Zero-day (computing)|zero day]]s) as well as those that have not been patched are still liable for exploitation.{{sfn|Daswani |Elbayadi|2021|pp=26-27}} Vulnerabilities vary in their ability to be [[Exploit (computer security)|exploit]]ed by malicious actors,{{sfn|Ablon|Bogart|2017|p=2}} and the actual risk is dependent on the nature of the vulnerability as well as the value of the surrounding system.{{sfn|Haber |Hibbert|2018|pp=5-6}} Although some vulnerabilities can only be used for [[denial of service]] attacks that compromise a system's availability, others allow the attacker to [[code injection|inject]] and run their own code (called [[malware]]), without the user being aware of it.{{sfn|Ablon|Bogart|2017|p=2}} To thwart cyberattacks, all software in the system must be designed to withstand and recover from external attack.{{sfn|O'Regan|2022|p=266}} Despite efforts to ensure security, a significant fraction of computers are infected with malware.{{sfn|Kitchin |Dodge|2011|p=37}} |
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===Execution=== |
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==Encoding and execution== |
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{{Main|Execution (computing)}} |
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Computer software has to be "loaded" into the computer's [[computer storage|storage]] (such as the [[hard drive]] or [[Computer memory|memory]]). Once the software has loaded, the computer is able to ''execute'' the software. This involves passing instructions from the application software, through the system software, to the hardware which ultimately receives the instruction as machine code. Each instruction causes the computer to carry out an operation—moving data, carrying out a [[computation]], or altering the [[control flow]] of instructions.{{Citation needed|date=September 2021}} |
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===Programming languages=== |
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Data movement is typically from one place in memory to another. Sometimes it involves moving data between memory and registers which enable high-speed data access in the CPU. Moving data, especially large amounts of it, can be costly; this is sometimes avoided by using "pointers" to data instead.{{Citation needed|date=September 2021}} Computations include simple operations such as incrementing the value of a variable data element. More complex computations may involve many operations and data elements together.{{Citation needed|date=September 2021}}<!-- This section is simply too long for this article and needs to be compressed into the intro above, or moved to the article itself. |
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{{main|Programming language}} |
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[[File:C Hello World Program.png|thumb|right|upright=1.3|The [[source code]] for a computer program in [[C (programming language)|C]]. The gray lines are [[comment (computer programming)|comments]] that explain the program to humans. When [[compiled]] and [[Execution (computing)|run]], it will give the output "[["Hello, World!" program|Hello, world!]]".]] |
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Programming languages are the format in which software is written. Since the 1950s, thousands of different programming languages have been invented; some have been in use for decades, while others have fallen into disuse.{{sfn|Tracy|2021|p=117}} Some definitions classify [[machine code]]—the exact instructions directly implemented by the hardware—and [[assembly language]]—a more human-readable alternative to machine code whose statements can be translated one-to-one into machine code—as programming languages.{{sfn|Tracy|2021|pp=118–120}} Programs written in the [[high-level programming languages]] used to create software share a few main characteristics: knowledge of machine code is not necessary to write them, they can be [[ported]] to other computer systems, and they are more concise and human-readable than machine code.{{sfn|Tracy|2021|pp=118–119}} They must be both human-readable and capable of being translated into unambiguous instructions for computer hardware.{{sfn|Kitchin |Dodge|2011|p=26}} |
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===Compilation, interpretation, and execution=== |
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Instructions may be performed sequentially, conditionally, or iteratively. Sequential instructions are those operations that are performed one after another. Conditional instructions are performed such that different sets of instructions execute depending on the value(s) of some data. In some languages this is known as an "if" statement. Iterative instructions are performed repetitively and may depend on some data value. This is sometimes called a "loop." Often, one instruction may "call" another set of instructions that are defined in some other program or [[modular programming|module]]. When more than one computer processor is used, instructions may be executed simultaneously. |
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<!-- [[File:Compiler.svg|upright=1.5|thumb |A diagram of the operation of a typical multi-language, multi-target compiler]] --> |
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The invention of high-level programming languages was simultaneous with the [[compiler]]s needed to translate them automatically into machine code.{{sfn|Tracy|2021|p=121}} Most programs do not contain all the resources needed to run them and rely on external [[software library|libraries]]. Part of the compiler's function is to link these files in such a way that the program can be executed by the hardware. Once compiled, the program can be saved as an [[object file]] and the [[Loader (computing)|loader]] (part of the operating system) can take this saved file and [[execution (computing)|execute]] it as a [[process]] on the computer hardware.{{sfn|Tracy|2021|pp=122-123}} Some programming languages use an [[Interpreter (computing)|interpreter]] instead of a compiler. An interpreter converts the program into machine code at [[execution (computing)|run time]], which makes them 10 to 100 times slower than compiled programming languages.{{sfn|O'Regan|2022|p=375}}{{sfn|Sebesta|2012|p=28}} |
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==Legal issues== |
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A simple example of the way software operates is what happens when a user selects an entry such as "Copy" from a menu. In this case, a conditional instruction is executed to copy text from data in a 'document' area residing in memory, perhaps to an intermediate storage area known as a 'clipboard' data area. If a different menu entry such as "Paste" is chosen, the software may execute the instructions to copy the text from the clipboard data area to a specific location in the same or another document in memory. |
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===Liability=== |
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{{main article|Software product liability}} |
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Depending on the application, even the example above could become complicated. The field of software engineering endeavors to manage the complexity of how software operates. This is especially true for software that operates in the context of a large or powerful [[computer system]]. |
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Software is often released with the knowledge that it is incomplete or contains bugs. Purchasers knowingly buy it in this state, which has led to a legal regime where [[liability]] for software products is significantly curtailed compared to other products.{{sfn|Kitchin |Dodge|2011|pp=36-37}} |
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===Licenses=== |
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Currently, almost the only limitations on the use of computer software in applications is the ingenuity of the designer/programmer. Consequently, large areas of activities (such as playing grand master-level chess) formerly assumed to be incapable of software simulation are now routinely programmed. The only area that has so far proved reasonably secure from software simulation is the realm of human art— especially, pleasing music and literature.{{Citation needed|date=June 2007}} |
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{{Main|Software license|Software copyright}} |
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[[File:Cube in Blender Editor.jpg|thumb|[[Blender (software)|Blender]], a [[free software]] program]] |
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Kinds of software by operation: [[computer program]] as [[executable]], [[source code]] or [[scripting language|script]], [[computer configuration|configuration]].--> |
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Source code is protected by [[copyright law]] that vests the owner with the exclusive right to copy the code. The underlying ideas or algorithms are not protected by copyright law, but are often treated as a [[trade secret]] and concealed by such methods as [[non-disclosure agreement]]s.{{sfn|O'Regan|2022|pp=394-396}} [[Software copyright]] has been recognized since the mid-1970s and is vested in the company that makes the software, not the employees or [[Independent contracting in the United States|contractor]]s who wrote it.{{sfn|O'Regan|2022|p=403}} The use of most software is governed by an agreement ([[software license]]) between the copyright holder and the user. [[Proprietary software]] is usually sold under a restrictive license that limits copying and reuse (often enforced with tools such as [[digital rights management]] (DRM)).{{sfn|O'Regan|2022|pp=394, 404}} [[Open-source licenses]], in contrast, allow free use and redistribution of software with few conditions.{{sfn|O'Regan|2022|p=403}} Most open-source licenses used for software require that modifications be released under the same license, which can create complications when open-source software is reused in proprietary projects.{{sfn|Langer|2016|pp=44-45}} |
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===Quality and reliability=== |
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{{Main|Software quality|Software testing}} |
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Software quality is very important, especially for [[commercial software|commercial]] and system software. If software is faulty, it can delete a person's work, crash the computer and do other unexpected things. Faults and errors are called "[[software bug|bugs]]" which are often discovered during alpha and beta testing.{{Citation needed|date=September 2021}} Software is often also a victim to what is known as [[software aging]], the progressive performance degradation resulting from a combination of unseen bugs.{{Citation needed|date=September 2021}} |
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Many bugs are discovered and fixed through [[software testing]]. However, software testing rarely—if ever—eliminates every bug; some programmers say that "every program has at least one more bug" (Lubarsky's Law).<ref name="github">{{cite web |date=2018-05-09 |title=scripting intelligence book examples |url=https://github.com/mark-watson/scripting-intelligence-book-examples/blob/master/part1/wikipedia_text/software.txt |url-status=live |archive-url=https://web.archive.org/web/20151106154317/https://github.com/mark-watson/scripting-intelligence-book-examples/blob/master/part1/wikipedia_text/software.txt |archive-date=6 November 2015 |access-date=2015-11-06 |website=[[GitHub]] |df=dmy-all}}</ref> In the [[Waterfall model|waterfall]] method of software development, separate testing teams are typically employed, but in newer approaches, collectively termed [[agile software development]], developers often do all their own testing, and demonstrate the software to users/clients regularly to obtain feedback.{{Citation needed|date=September 2021}} Software can be tested through [[unit testing]], [[regression testing]] and other methods, which are done manually, or most commonly, automatically, since the amount of code to be tested can be large.{{Citation needed|date=September 2021}} Programs containing command software enable hardware engineering and system operations to function much easier together.<ref>{{Cite web |title=What is System Software? – Definition from WhatIs.Com |url=https://www.techtarget.com/whatis/definition/system-software |access-date=2023-02-27 |website=WhatIs.com |language=en |archive-date=27 February 2023 |archive-url=https://web.archive.org/web/20230227150703/https://www.techtarget.com/whatis/definition/system-software |url-status=live }}</ref> |
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===License=== |
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{{Main|Software license}} |
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The software's license gives the user the right to use the software in the licensed environment, and in the case of [[free software license]]s, also grants other rights such as the right to make copies.<ref>{{Cite web |title=What is a Software License? Everything You Need to Know |url=https://www.techtarget.com/searchcio/definition/software-license |access-date=2023-02-27 |website=CIO |language=en |archive-date=27 February 2023 |archive-url=https://web.archive.org/web/20230227150704/https://www.techtarget.com/searchcio/definition/software-license |url-status=live }}</ref> |
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[[Proprietary software]] can be divided into two types: |
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* [[freeware]], which includes the category of "free trial" software or "[[freemium]]" software (in the past, the term [[shareware]] was often used for free trial/freemium software). As the name suggests, freeware can be used for free, although in the case of free trials or freemium software, this is sometimes only true for a limited period of time or with limited functionality.<ref>{{Cite web |title=Freeware vs Shareware - Difference and Comparison {{!}} Diffen |url=https://www.diffen.com/difference/Freeware_vs_Shareware |url-status=live |access-date=2022-01-26 |website=www.diffen.com |language=en |archive-date=26 January 2022 |archive-url=https://web.archive.org/web/20220126171419/https://www.diffen.com/difference/Freeware_vs_Shareware }}</ref> |
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* software available for a fee, which can only be legally used on purchase of a license.<ref>{{Cite journal |last1=Morin |first1=Andrew |last2=Urban |first2=Jennifer |last3=Sliz |first3=Piotr |date=2012-07-26 |title=A Quick Guide to Software Licensing for the Scientist-Programmer |journal=PLOS Computational Biology |language=en |volume=8 |issue=7 |pages=e1002598 |doi=10.1371/journal.pcbi.1002598 |issn=1553-7358 |pmc=3406002 |pmid=22844236|bibcode=2012PLSCB...8E2598M |doi-access=free }}</ref> |
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[[Open-source software]] comes with a free software license, granting the recipient the rights to modify and redistribute the software.<ref>{{Cite web |title=Open source software explained |url=https://www.ionos.ca/digitalguide/server/know-how/what-is-open-source/ |url-status=live |access-date=2022-01-26 |website=IONOS Digitalguide |language=en-US |archive-date=26 January 2022 |archive-url=https://web.archive.org/web/20220126171422/https://www.ionos.ca/digitalguide/server/know-how/what-is-open-source/ }}</ref> |
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===Patents=== |
===Patents=== |
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{{Main|Software patent|Software patent debate}} |
{{Main|Software patent|Software patent debate}} |
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[[Patent]]s give an inventor an exclusive, time-limited license for a novel product or process.{{sfn|O'Regan|2022|p=395}} Ideas about what software could accomplish are not protected by law and concrete implementations are instead covered by [[copyright law]]. In some countries, a requirement for the claimed invention to have an effect on the physical world may also be part of the requirements for a software patent to be held valid.<ref>Gerardo Con Díaz, "The Text in the Machine: American Copyright Law and the Many Natures of Software, 1974–1978", ''Technology and Culture'' 57 (October 2016), 753–79.</ref> [[Software patent]]s have been [[Software patent debate|historically controversial]]. Before the 1998 case ''[[State Street Bank & Trust Co. v. Signature Financial Group, Inc.]]'', software patents were generally not recognized in the United States. In that case, the [[Supreme Court]] decided that business processes could be patented.{{sfn|Jones|2014|p=19}} Patent applications are complex and costly, and lawsuits involving patents can drive up the cost of products.{{sfn|O'Regan|2022|p=398}} Unlike copyrights, patents generally only apply in the jurisdiction where they were issued.{{sfn|O'Regan|2022|p=399}} |
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==Impact== |
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Software patents are controversial in the software industry with many people holding different views about them. One of the sources of controversy is that the aforementioned split between initial ideas and patent does not seem to be honored in practice by patent lawyers—for example the patent for [[aspect-oriented programming]] (AOP), which purported to claim rights over ''any'' programming tool implementing the idea of AOP, howsoever implemented.{{Citation needed|date=September 2021}} Another source of controversy is the effect on innovation, with many distinguished experts and companies arguing that software is such a fast-moving field that software patents merely create vast additional litigation costs and risks, and actually retard innovation.{{Citation needed|date=September 2021}} In the case of debates about software patents outside the United States, the argument has been made that large American corporations and patent lawyers are likely to be the primary beneficiaries of allowing or continue to allow software patents.{{Citation needed|date=September 2021}} |
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{{further |Information Age}} |
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<!-- [[File:Elderly Man Using Pulse Oximeter.jpg|thumb|Many everyday objects such as the [[pulse oximeter]] the man is using are actually [[embedded system]]s that require software to function.{{sfn|Kitchin |Dodge|2011|p=47}}{{sfn|Jones|2014|p=xxviii}}]] --> |
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==Design and implementation== |
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[[File:A computer graphic of the Queen Elizabeth carrier and carrier group.jpg|thumb|Computer-generated simulations are one of the advances enabled by software.{{sfn|Manovich|2013|p=333}}]] |
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{{Main|Software development|Computer programming|Software engineering}} |
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Engineer [[Capers Jones]] writes that "computers and software are making profound changes to every aspect of human life: education, work, warfare, entertainment, medicine, law, and everything else".{{sfn|Jones|2014|p=32}} It has become ubiquitous in [[everyday life]] in [[developed countries]].{{sfn|Kitchin |Dodge|2011|p=iv}} In many cases, software augments the functionality of existing technologies such as household [[Home appliance|appliances]] and [[elevator]]s.{{sfn|Kitchin |Dodge|2011|p=5}} Software also spawned entirely new technologies such as [[the Internet]], [[video games]], [[mobile phones]], and [[GPS]].{{sfn|Kitchin |Dodge|2011|p=5}}{{sfn|Jones|2014|p=xxviii}} New methods of communication, including [[email]], [[Internet forum|forum]]s, [[blog]]s, [[microblogging]], [[wiki]]s, and [[social media]], were enabled by the Internet.{{sfn|Manovich|2013|p=329}} Massive amounts of knowledge exceeding any paper-based library are now available with a quick [[web search]].{{sfn|Jones|2014|p=xxviii}} Most creative professionals have switched to software-based tools such as [[computer-aided design]], [[3D modeling]], digital [[image editing]], and [[computer animation]].{{sfn|Manovich|2013|p=333}} Almost every complex device is controlled by software.{{sfn|Jones|2014|p=xxviii}} |
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Design and implementation of software vary depending on the complexity of the software. For instance, the design and creation of [[Microsoft Word]] took much more time than designing and developing [[Microsoft Notepad]] because the former has much more basic functionality.{{Citation needed|date=September 2021}} |
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Software is usually developed in [[integrated development environment]]s (IDE) like [[Eclipse (software)|Eclipse]], [[IntelliJ IDEA|IntelliJ]] and [[Microsoft Visual Studio]] that can simplify the process and [[compiler|compile]] the software.<ref name="alan">{{cite web |last=Constantin |first=Alin |title=Microsoft Source Code Control Interface |url=http://alinconstantin.dtdns.net/webdocs/scc/MSSCCI.htm |url-status=dead |archive-url=https://web.archive.org/web/20080218111934/http://alinconstantin.dtdns.net/webdocs/scc/MSSCCI.htm |archive-date=February 18, 2008 |access-date=January 3, 2008 |website=Alin Constantin}}</ref> As noted in a different section, software is usually created on top of existing software and the [[application programming interface]] (API) that the underlying software provides like [[GTK+]], JavaBeans or [[Swing (Java)|Swing]].{{Citation needed|date=September 2021}} Libraries (APIs) can be categorized by their purpose. For instance, the [[Spring Framework]] is used for implementing [[enterprise application]]s, the [[Windows Forms]] library is used for designing graphical user interface (GUI) applications like Microsoft Word, and [[Windows Communication Foundation]] is used for designing [[web service]]s.{{Citation needed|date=September 2021}} When a program is designed, it relies upon the API. For instance, a Microsoft Windows desktop application might call API functions in the [[.NET Framework|.NET]] Windows Forms library like ''Form1.Close()'' and ''Form1.Show()''<ref>{{cite web |title=MSDN Library |url=http://msdn.microsoft.com/en-us/library/default.aspx |url-status=live |archive-url=https://web.archive.org/web/20100611204810/http://msdn.microsoft.com/en-us/library/default.aspx |archive-date=11 June 2010 |access-date=2010-06-14 |website=Microsoft |df=dmy-all}}</ref> to close or open the application. Without these APIs, the programmer needs to write these functionalities entirely themselves. Companies like [[Oracle Corporation|Oracle]] and [[Microsoft]] provide their own APIs so that many applications are written using their [[library (computing)|software libraries]] that usually have numerous APIs in them.{{Citation needed|date=September 2021}} |
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[[Data structure]]s such as [[hash table]]s, [[array data type|arrays]], and [[binary tree]]s, and [[algorithm]]s such as [[quicksort]], can be useful for creating software. |
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Computer software has special economic characteristics that make its design, creation, and distribution different from most other economic goods.{{Specify|Which characteristics?|date=May 2012}}<ref>{{cite journal |author=v. Engelhardt, Sebastian |year=2008 |url=https://ideas.repec.org/p/jrp/jrpwrp/2008-045.html |title=The Economic Properties of Software |journal=Jena Economic Research Papers |volume=2 |issue=2008–045 |url-status=live |archive-url=https://web.archive.org/web/20160105145954/https://ideas.repec.org/p/jrp/jrpwrp/2008-045.html |archive-date=5 January 2016 |df=dmy-all }}</ref><ref>{{cite web |last=Kaminsky |first=Dan |date=1999-03-02 |title=Why Open Source Is The Optimum Economic Paradigm for Software |url=http://dankaminsky.com/1999/03/02/69/ |url-status=live |archive-url=https://web.archive.org/web/20120522001231/http://dankaminsky.com/1999/03/02/69/ |archive-date=22 May 2012 |access-date=2021-11-19 |website=dankaminsky.com |language=en-US |df=dmy-all}}</ref> |
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A person who creates software is called a [[programmer]], [[software engineer]] or software developer, terms that all have a similar meaning. More informal terms for programmer also exist such as "coder" and "hacker"{{Spaced ndash}}although use of the latter word may cause confusion, because it is more often used to mean [[security hacker|someone who illegally breaks into computer systems]]. |
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==See also== |
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* [[Computer program]] |
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* [[Independent software vendor]] |
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* [[Internetware]] |
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* [[Open-source software]] |
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* [[Outline of software]] |
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* [[Software asset management]] |
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* [[Software release life cycle]] |
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==References== |
==References== |
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{{reflist |
{{reflist}} |
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<ref name="Carhart_1953">{{cite book |author-last=Carhart |author-first=Richard |title=A survey of the current status of the electronic reliability problem |date=1953 |publisher=[[Rand Corporation]] |location=Santa Monica, CA |page=69 |url=https://www.rand.org/content/dam/rand/pubs/research_memoranda/2013/RM1131.pdf#79 |archive-url=https://ghostarchive.org/archive/20221009/https://www.rand.org/content/dam/rand/pubs/research_memoranda/2013/RM1131.pdf#79 |archive-date=2022-10-09 |url-status=live |quote=[…] It will be recalled from Sec. 1.6 that the term ''personnel'' was defined to include people who come into direct contact with the hardware, from production to field use, i.e., people who assemble, inspect, pack, ship, handle, install, operate, and maintain electronic equipment. In any of these phases personnel failures may result in unoperational gear. As with the hardware factors, there is almost no quantitative data concerning these software or human factors in reliability: How many faults are caused by personnel, why they occur, and what can be done to remove the errors. […]}}</ref> |
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<ref name="Tukey_1958">{{cite journal |author-first=John Wilder |author-last=Tukey |author-link=John Wilder Tukey |title=The Teaching of Concrete Mathematics |journal=[[American Mathematical Monthly]] |publisher=[[Taylor & Francis, Ltd.]] / [[Mathematical Association of America]] |volume=65 |issue=1 |pages=1–9, 2 |date=January 1958 |id={{CODEN|AMMYAE}} |issn=0002-9890 |doi=10.2307/2310294 |quote=[…] Today the "software" comprising the carefully planned interpretive routines, compilers, and other aspects of automative programming are at least as important to the modern electronic calculator as its "hardware" of tubes, transistors, wires, tapes, and the like. […]|jstor=2310294 }}</ref> |
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<ref name="Niquette_2006">{{citation |author-last=Niquette |author-first=R. Paul |date=2006 |title=Softword: Provenance for the Word 'Software |isbn=1-58922-233-4 |url=http://www.niquette.com/books/softword/tocsoft.html |access-date=2019-08-18 |url-status=live |archive-url=https://web.archive.org/web/20190808124650/http://www.niquette.com/books/softword/tocsoft.html |archive-date=2019-08-08}}</ref> |
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<ref name="Shapiro_2000">{{cite journal |author-last=Shapiro |author-first=Fred |date=2000 |title=Origin of the Term Software: Evidence from the JSTOR Electronic Journal Archive |journal=[[IEEE Annals of the History of Computing]] |volume=22 |issue=2 |pages=69–71 |doi=10.1109/mahc.2000.887997 |url=http://computer.org/annals/an2000/pdf/a2069.pdf |access-date=2013-06-25 |url-status=dead |archive-url=https://web.archive.org/web/20030605004419/http://computer.org/annals/an2000/pdf/a2069.pdf |archive-date=2003-06-05}}</ref> |
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<ref name="Leonhardt_2000">{{cite news |title=John Tukey, 85, Statistician; Coined the Word 'Software' |author-last=Leonhardt |author-first=David |newspaper=[[The New York Times]] |date=2000-07-28 |url=https://www.nytimes.com/2000/07/28/us/john-tukey-85-statistician-coined-the-word-software.html |access-date=2012-09-24 |archive-date=16 June 2021 |archive-url=https://web.archive.org/web/20210616140125/http://www.nytimes.com/2000/07/28/us/john-tukey-85-statistician-coined-the-word-software.html |url-status=live }}</ref> |
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<ref name="Beebe_2017">{{cite book |author-first=Nelson H. F. |author-last=Beebe |title=The Mathematical-Function Computation Handbook - Programming Using the MathCW Portable Software Library |chapter=Chapter I - Integer arithmetic |date=2017-08-22 |location=Salt Lake City, UT, US |publisher=[[Springer International Publishing AG]] |edition=1 |lccn=2017947446 |isbn=978-3-319-64109-6 |doi=10.1007/978-3-319-64110-2 |pages=969, 1035|s2cid=30244721 }}</ref> |
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}} |
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===Sources=== |
===Sources=== |
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{{refbegin|indent=yes}} |
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* {{Cite book|url=https://books.google.com/books?id=C8ouDwAAQBAJ&q=9780735211759&pg=PP1|title=Broad Band: The Untold Story of the Women Who Made the Internet|last=Evans|first=Claire L.|publisher=Portfolio/Penguin|year=2018|isbn=9780735211759|location=New York}} |
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*{{cite book |last1=Ablon |first1=Lillian |last2=Bogart |first2=Andy |title=Zero Days, Thousands of Nights: The Life and Times of Zero-Day Vulnerabilities and Their Exploits |date=2017 |publisher=Rand Corporation |isbn=978-0-8330-9761-3 |language=en|url=https://www.rand.org/content/dam/rand/pubs/research_reports/RR1700/RR1751/RAND_RR1751.pdf}} |
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*{{cite book |last1=Anderson |first1=Thomas |last2=Dahlin |first2=Michael |author1-link=Thomas E. Anderson |title=Operating Systems: Principles and Practice |date=2014 |publisher=Recursive Books |isbn=978-0-9856735-2-9 |edition=2 |language=en}} |
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==External links== |
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*{{cite book |last1=Campbell-Kelly |first1=Martin |last2=Garcia-Swartz |first2=Daniel D. |title=From Mainframes to Smartphones: A History of the International Computer Industry |date=2015 |publisher=Harvard University Press |isbn=978-0-674-28655-9 |language=en}} |
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* [https://www.britannica.com/technology/software Software] at ''[[Encyclopædia Britannica]]'' |
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*{{cite book |last1=Daswani |first1=Neil|authorlink=Neil Daswani |last2=Elbayadi |first2=Moudy |title=Big Breaches: Cybersecurity Lessons for Everyone |date=2021 |publisher=Apress |isbn=978-1-4842-6654-0}} |
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* {{curlie|Computers/Software}}<!--ref name="github"/--> |
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*{{Cite book |last=Dooley |first=John F. |title=Software Development, Design and Coding: With Patterns, Debugging, Unit Testing, and Refactoring |date=2017 |publisher=Apress |isbn=978-1-4842-3153-1 |language=en}} |
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*{{cite book |last1=Gabbrielli |first1=Maurizio |last2=Martini |first2=Simone |title=Programming Languages: Principles and Paradigms |date=2023 |publisher=Springer |isbn=978-3-031-34144-1 |language=en|edition=2nd}} |
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*{{cite book |last1=Galin |first1=Daniel |title=Software Quality: Concepts and Practice |date=2018 |publisher=John Wiley & Sons |isbn=978-1-119-13449-7 |language=en}} |
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*{{cite book |last1=Haber |first1=Morey J. |last2=Hibbert |first2=Brad |title=Asset Attack Vectors: Building Effective Vulnerability Management Strategies to Protect Organizations |date=2018 |publisher=Apress |isbn=978-1-4842-3627-7 |language=en}} |
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*{{cite book |last1=Jones |first1=Capers |title=The Technical and Social History of Software Engineering |date=2014 |publisher=Pearson Education |isbn=978-0-321-90342-6 |language=en}} |
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*{{cite book |last1=Kitchin |first1=Rob |last2=Dodge |first2=Martin |title=Code/space: Software and Everyday Life |date=2011 |publisher=MIT Press |isbn=978-0-262-04248-2 |language=en}} |
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*{{Cite book |last=Langer |first=Arthur M. |title=Guide to Software Development: Designing and Managing the Life Cycle |date=2016 |publisher=Springer |isbn=978-1-4471-6799-0 |language=en}} |
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*{{cite book |last1=Manovich |first1=Lev |title=Software Takes Command |date=2013 |publisher=Bloomsbury Academic |isbn=978-1-62356-745-3 |language=en}} |
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*{{cite book |last1=O'Regan |first1=Gerard |title=Concise Guide to Software Engineering: From Fundamentals to Application Methods |date=2022 |publisher=Springer Nature |isbn=978-3-031-07816-3 |language=en}} |
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*{{cite book |last1=Osterweil |first1=Leon J. |title=Perspectives on the Future of Software Engineering: Essays in Honor of Dieter Rombach |date=2013 |publisher=Springer |isbn=978-3-642-37395-4 |pages=237–254 |language=en |chapter=What Is Software? The Role of Empirical Methods in Answering the Question}} |
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*{{cite journal |last1=Rahman |first1=Hanif Ur |last2=da Silva |first2=Alberto Rodrigues |last3=Alzayed |first3=Asaad |last4=Raza |first4=Mushtaq |title=A Systematic Literature Review on Software Maintenance Offshoring Decisions |journal=Information and Software Technology |date=2024 |volume=172 |pages=107475 |doi=10.1016/j.infsof.2024.107475|ref={{sfnref|Rahman et al.|2024}}}} |
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*{{cite book |last1=Reifer |first1=Donald J. |title=Software Maintenance Success Recipes |date=2012 |publisher=CRC Press |isbn=978-1-4398-5167-8 |language=en}} |
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*{{cite book |last1=Rosati |first1=Pierangelo |last2=Lynn |first2=Theo |title=Measuring the Business Value of Cloud Computing |date=2020 |publisher=Springer International Publishing |isbn=978-3-030-43198-3 |pages=19–37 |language=en |chapter=Measuring the Business Value of Infrastructure Migration to the Cloud}} |
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* {{cite book |last1=Sebesta |first1=Robert W. |title=Concepts of Programming Languages |date=2012 |publisher=Addison-Wesley |isbn=978-0-13-139531-2 |edition=10 |language=en}} |
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*{{cite book |last1=Stull |first1=Edward |title=UX Fundamentals for Non-UX Professionals: User Experience Principles for Managers, Writers, Designers, and Developers |date=2018 |publisher=Apress |isbn=978-1-4842-3811-0 |language=en}} |
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*{{cite book |last1=Tanenbaum |first1=Andrew S.|authorlink=Andrew S. Tanenbaum |last2=Bos |first2=Herbert |title=Modern Operating Systems, Global Edition |date=2023 |publisher=Pearson Higher Ed |isbn=978-1-292-72789-9 |language=en}} |
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*{{cite book |last1=Tracy |first1=Kim W. |title=Software: A Technical History |date=2021 |publisher=Morgan & Claypool Publishers |isbn=978-1-4503-8724-8 |language=en}} |
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*{{cite book |last1=Tripathy |first1=Priyadarshi |last2=Naik |first2=Kshirasagar |title=Software Evolution and Maintenance: A Practitioner's Approach |date=2014 |publisher=John Wiley & Sons |isbn=978-0-470-60341-3 |language=en}} |
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*{{Cite book |last=Tucker |first=Allen |title=Software Development: An Open Source Approach |last2=Morelli |first2=Ralph |last3=de Silva |first3=Chamindra |date=2011 |publisher=CRC Press |isbn=978-1-4398-8460-7 |language=en}} |
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*{{cite journal |last1=Ulziit |first1=Bayarbuyan |last2=Warraich |first2=Zeeshan Akhtar |last3=Gencel |first3=Cigdem |last4=Petersen |first4=Kai |title=A conceptual framework of challenges and solutions for managing global software maintenance |journal=Journal of Software: Evolution and Process |date=2015 |volume=27 |issue=10 |pages=763–792 |doi=10.1002/smr.1720|ref={{sfnref|Ulziit et al.|2015}}}} |
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*{{cite book |last1=Watt |first1=Andy |title=Building Modern SaaS Applications with C# And . NET: Build, Deploy, and Maintain Professional SaaS Applications |date=2023 |publisher=Packt |isbn=978-1-80461-087-9 |language=en}} |
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*{{cite book |last1=Varga |first1=Ervin |title=Unraveling Software Maintenance and Evolution: Thinking Outside the Box |date=2018 |publisher=Springer |isbn=978-3-319-71303-8 |language=en}} |
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{{refend}} |
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{{subject bar|Free and open-source software|auto=1}} |
{{subject bar|Free and open-source software|auto=1}} |
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Revision as of 09:21, 30 May 2024
Software is defined narrowly as unambiguous instructions that can be transformed into a form executable on computer hardware, or more broadly including supporting concepts, tools and methods needed to make the computer system operational.
Building off of previous innovations in mathematics and technology, software was created for the programmable digital computers that emerged in the late 1940s and was necessary to realize their usefulness. The first software was tied closely to the underlying computer hardware, but over time, the lower layers of the system have become more standardized, and software has become increasingly portability between different systems and abstracted from the underlying machine code. Operating systems manage the hardware resources and mediate between different applications that accomplish tasks for the user. Programming languages are the format in which software is written, and must be both human-readable and capable of being translated into unambiguous instructions for computer hardware. Compilers or interpreters are needed to link a program with other code that it relies on and convert the software into machine code that can be executed on the hardware. Programs are combined with each other and with external input to be capable of accomplishing a complex task.
Programming and maintaining the source code is the central step of software development, but it also includes conceiving the project, evaluating its feasibility, analyzing the business requirements, software design, and release. Software quality assurance, including code review and testing, is an essential part of the process as delivering quality code lowers the cost of reliability failures, cyberattacks enabled by security vulnerabilities, and maintenance cost. Maintenance typically consumes 75 percent or more of the software's lifetime engineering budget. Source code is protected by copyright law that vests the owner with the exclusive right to copy the code. Software has become ubiquitous in everyday life in developed countries. In many cases, software augments the functionality of pre-existing technologies, but it has also enabled the creation of entirely new technologies such as the Internet, video games, social media, mobile phones, and GPS.
Definition
Software can be defined more narrowly as the instructions executed by the computer hardware, or more broadly including other concepts, tools, and methods needed to make an executable system on computer hardware, such as design documents, specifications, and testing suites.[2][3] An individual program or source code file consists of unambiguous instructions and algorithms. Programs are combined with each other and with external input to be capable of accomplishing a complex task.[4][3] Tools such as compilers, assemblers, flowcharts, design tools, simulators, and architectural diagrams—some of which are also software—are essential to the design and execution of most computing systems.[3] Although software is intangible,[5][6] software makes instructions for computer hardware to produce visible and tangible effects.[7]
History
A host of earlier inventions were necessary for the creation of software, including mathematics—especially binary and decimal number systems, and zero—alphabets, writing, mechanical calculators,[9] boolean algebra, transistors, integrated circuits, and plastics.[10] Software could not exist without digital computers, as it was created specifically for these devices and was necessary to realize their usefulness.[11]
The first programmable computers, which appeared at the end of the 1940s,[12] were programmed in machine language (simple instructions that could be directly executed by the processor). Machine language was difficult to debug and was not portable between different computer systems.[13] Initially, hardware resources were scarce and expensive, while human resources were cheaper.[14] As programs grew more complex, programmer productivity became a bottleneck. This led to the introduction of high-level programming languages in the mid-1950s. These languages abstracted away the details of the hardware, instead being designed to express algorithms that could be understood more easily by humans.[15][16] As instructions distinct from the underlying computer hardware, software is therefore relatively recent, dating to these early high-level programming languages such as Fortran, Lisp, and Cobol.[16] The first use of the word software is credited to mathematician John Wilder Tukey in 1958.[3]
The first software was tied closely to the underlying hardware and consequently was not portable to other systems. As it has evolved, newer software can be built and run on a wide variety of platforms. Much of the increase in portability can be attributed to standardization of lower-level aspects of the system, such as networking, operating systems, and databases. Because there are only a relatively few operating systems, TCP and IP are used for virtually all networking, and SQL is used for many database queries, application software can run more easily over a wide variety of hardware.[17] Increasing the number of layers of abstraction in the system is a related development: both in programming languages where it enables better structure and increased modularity, as well as enabling virtualization of system resources. As a result of the increase in stability and abstraction, software has become increasingly complex and can solve more problems.[18] Both industry and academia have had a strong influence on the development of different aspects of software.[19]
Types
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There are two main types of software:
- Operating systems are "the layer of software that manages a computer's resources for its users and their applications".[20] There are three main purposes that an operating system fulfills:[21]
- Allocating resources between different applications, deciding when they will receive central processing unit (CPU) time or space in memory.[21]
- Providing an interface that abstracts the details of accessing hardware details (like physical memory) to make things easier for programmers.[21][22]
- Offering common services, such as an interface for accessing network and disk devices. This enables an application to be run on different hardware without needing to be rewritten.[23]
- Application software runs on top of the operating system and uses the computer's resources to perform a task.[24] There are many different types of application software because the range of tasks that can be performed with modern computers is so large.[25] Applications account for most software[26] and require the environment provided by an operating system, and often other applications, in order to function.[27]
Software can also be categorized by how it is deployed. Traditional applications are purchased with a perpetual license for a specific version of the software, downloaded, and run on hardware belonging to the purchaser.[28] The rise of the Internet and cloud computing enabled a new model, software as a service (SaaS),[29] in which the provider hosts the software (usually built on top of rented infrastructure or platforms)[30] and provides the use of the software to customers, often in exchange for a subscription fee.[28] By 2023, SaaS products—which are usually delivered via a web application—had become the primary method that companies deliver applications.[31]
Software development and maintenance
Software companies aim to deliver a high-quality product on time and under budget. A challenge is that software development effort estimation is often inaccurate.[32] Software development begins by conceiving the project, evaluating its feasibility, analyzing the business requirements, and making a software design.[33][34] Most software projects speed up their development by reusing or incorporating existing software, either in the form of commercial off-the-shelf (COTS) or open-source software.[35][36] Software quality assurance is typically a combination of manual code review by other engineers[37] and automated software testing. Due to time constraints, testing cannot cover all aspects of the software's intended functionality, so developers often focus on the most critical functionality.[38] Formal methods are used in some safety-critical systems to prove the correctness of code,[39] while user acceptance testing helps to ensure that the product meets customer expectations.[40] There are a variety of software development methodologies, which vary to completing all steps in order to concurrent and iterative models.[41] Software development is driven by requirements taken from prospective users, as opposed to maintenance that is driven by events such as a change request.[42]
Frequently, software is released in an incomplete state when the development team runs out of time or funding.[43] Despite testing and quality assurance, virtually all software contains bugs where the system does not work as intended. Post-release software maintenance is necessary to remediate these bugs when they are found and keep the software working as its the environment changes over time.[44] New features are often added after release. Over time, the level of maintenance becomes increasingly restricted before being cut off entirely when the product is withdrawn from the market.[45] As software ages, it becomes known as legacy software and can remain in use for decades, even if there is no one left who knows how to fix it.[5] Over the lifetime of the product, software maintenance is estimated to comprise 75 percent or more of the total development cost.[46][47]
Completing a software project involves various forms of expertise, not just in software programmers but also testing, documentation writing, project management, graphic design, user experience, user support, marketing, and fundraising.[48][49][34]
Quality and security
Software quality is defined as meeting the stated requirements as well as customer expectations.[50] Quality is an overarching term that can refer to a code's correct and efficient behavior, its reusability and portability, or the ease of modification.[51] It is usually more cost-effective to build quality into the product from the beginning rather than try to add it later in the development process.[52] Higher quality code will reduce lifetime cost to both suppliers and customers as it is more reliable and easier to maintain.[53][54] Software failures in safety-critical systems can be very serious including death.[53] By some estimates, the cost of poor quality software can be as high as 20 to 40 percent of sales.[55] Despite developers' goal of delivering a product that works entirely as intended, virtually all software contains bugs.[56]
The rise of the Internet also greatly increased the need for computer security as it enabled malicious actors to conduct cyberattacks remotely.[57][58] If a bug creates a security risk, it is called a vulnerability.[59][60] Software patches are often released to fix identified vulnerabilities, but those that remain unknown (zero days) as well as those that have not been patched are still liable for exploitation.[61] Vulnerabilities vary in their ability to be exploited by malicious actors,[59] and the actual risk is dependent on the nature of the vulnerability as well as the value of the surrounding system.[62] Although some vulnerabilities can only be used for denial of service attacks that compromise a system's availability, others allow the attacker to inject and run their own code (called malware), without the user being aware of it.[59] To thwart cyberattacks, all software in the system must be designed to withstand and recover from external attack.[58] Despite efforts to ensure security, a significant fraction of computers are infected with malware.[63]
Encoding and execution
Programming languages
Programming languages are the format in which software is written. Since the 1950s, thousands of different programming languages have been invented; some have been in use for decades, while others have fallen into disuse.[64] Some definitions classify machine code—the exact instructions directly implemented by the hardware—and assembly language—a more human-readable alternative to machine code whose statements can be translated one-to-one into machine code—as programming languages.[65] Programs written in the high-level programming languages used to create software share a few main characteristics: knowledge of machine code is not necessary to write them, they can be ported to other computer systems, and they are more concise and human-readable than machine code.[66] They must be both human-readable and capable of being translated into unambiguous instructions for computer hardware.[67]
Compilation, interpretation, and execution
The invention of high-level programming languages was simultaneous with the compilers needed to translate them automatically into machine code.[68] Most programs do not contain all the resources needed to run them and rely on external libraries. Part of the compiler's function is to link these files in such a way that the program can be executed by the hardware. Once compiled, the program can be saved as an object file and the loader (part of the operating system) can take this saved file and execute it as a process on the computer hardware.[69] Some programming languages use an interpreter instead of a compiler. An interpreter converts the program into machine code at run time, which makes them 10 to 100 times slower than compiled programming languages.[70][71]
Legal issues
Liability
Software is often released with the knowledge that it is incomplete or contains bugs. Purchasers knowingly buy it in this state, which has led to a legal regime where liability for software products is significantly curtailed compared to other products.[72]
Licenses
Source code is protected by copyright law that vests the owner with the exclusive right to copy the code. The underlying ideas or algorithms are not protected by copyright law, but are often treated as a trade secret and concealed by such methods as non-disclosure agreements.[73] Software copyright has been recognized since the mid-1970s and is vested in the company that makes the software, not the employees or contractors who wrote it.[74] The use of most software is governed by an agreement (software license) between the copyright holder and the user. Proprietary software is usually sold under a restrictive license that limits copying and reuse (often enforced with tools such as digital rights management (DRM)).[75] Open-source licenses, in contrast, allow free use and redistribution of software with few conditions.[74] Most open-source licenses used for software require that modifications be released under the same license, which can create complications when open-source software is reused in proprietary projects.[76]
Patents
Patents give an inventor an exclusive, time-limited license for a novel product or process.[77] Ideas about what software could accomplish are not protected by law and concrete implementations are instead covered by copyright law. In some countries, a requirement for the claimed invention to have an effect on the physical world may also be part of the requirements for a software patent to be held valid.[78] Software patents have been historically controversial. Before the 1998 case State Street Bank & Trust Co. v. Signature Financial Group, Inc., software patents were generally not recognized in the United States. In that case, the Supreme Court decided that business processes could be patented.[10] Patent applications are complex and costly, and lawsuits involving patents can drive up the cost of products.[79] Unlike copyrights, patents generally only apply in the jurisdiction where they were issued.[80]
Impact
Engineer Capers Jones writes that "computers and software are making profound changes to every aspect of human life: education, work, warfare, entertainment, medicine, law, and everything else".[82] It has become ubiquitous in everyday life in developed countries.[83] In many cases, software augments the functionality of existing technologies such as household appliances and elevators.[1] Software also spawned entirely new technologies such as the Internet, video games, mobile phones, and GPS.[1][84] New methods of communication, including email, forums, blogs, microblogging, wikis, and social media, were enabled by the Internet.[85] Massive amounts of knowledge exceeding any paper-based library are now available with a quick web search.[84] Most creative professionals have switched to software-based tools such as computer-aided design, 3D modeling, digital image editing, and computer animation.[81] Almost every complex device is controlled by software.[84]
References
- ^ a b c Kitchin & Dodge 2011, p. 5.
- ^ Osterweil 2013, p. 61.
- ^ a b c d Tracy 2021, p. 2.
- ^ Kitchin & Dodge 2011, pp. 3, 24.
- ^ a b Tracy 2021, p. 3.
- ^ Kitchin & Dodge 2011, p. 24.
- ^ Kitchin & Dodge 2011, pp. 3–4.
- ^ Jones 2014, pp. 19, 22.
- ^ Jones 2014, pp. 9, 21.
- ^ a b Jones 2014, p. 19.
- ^ Jones 2014, p. 22.
- ^ Gabbrielli & Martini 2023, p. 519.
- ^ Gabbrielli & Martini 2023, pp. 520–521.
- ^ Gabbrielli & Martini 2023, p. 522.
- ^ Gabbrielli & Martini 2023, p. 521.
- ^ a b Tracy 2021, p. 1.
- ^ Tracy 2021, p. 249.
- ^ Tracy 2021, p. 250.
- ^ Tracy 2021, pp. 250–251.
- ^ Anderson & Dahlin 2014, p. 6.
- ^ a b c Anderson & Dahlin 2014, p. 7.
- ^ Tanenbaum & Bos 2023, p. 5.
- ^ Anderson & Dahlin 2014, pp. 7, 9, 13.
- ^ Anderson & Dahlin 2014, pp. 6–7.
- ^ Jones 2014, p. 121.
- ^ Tracy 2021, p. 66.
- ^ Tracy 2021, p. 72.
- ^ a b O'Regan 2022, p. 386.
- ^ Campbell-Kelly & Garcia-Swartz 2015, pp. 156–157.
- ^ Rosati & Lynn 2020, p. 23.
- ^ Watt 2023, p. 4.
- ^ O'Regan 2022, p. 7.
- ^ O'Regan 2022, p. 5.
- ^ a b Dooley 2017, p. 1.
- ^ O'Regan 2022, pp. 18, 110–111.
- ^ Tracy 2021, pp. 43, 76.
- ^ O'Regan 2022, pp. 117–118.
- ^ O'Regan 2022, p. 54.
- ^ O'Regan 2022, p. 267.
- ^ O'Regan 2022, p. 20.
- ^ O'Regan 2022, p. 9.
- ^ Tripathy & Naik 2014, p. 26.
- ^ Reifer 2012, p. 22.
- ^ Tripathy & Naik 2014, pp. 4, 27.
- ^ Tripathy & Naik 2014, p. 89.
- ^ Varga 2018, p. 6.
- ^ Ulziit et al. 2015, p. 764.
- ^ Tucker, Morelli & de Silva 2011, p. 7.
- ^ Stull 2018, pp. 24–25.
- ^ Galin 2018, p. 3.
- ^ Galin 2018, p. 26.
- ^ O'Regan 2022, pp. 68, 117.
- ^ a b O'Regan 2022, pp. 3, 268.
- ^ Varga 2018, p. 12.
- ^ O'Regan 2022, p. 119.
- ^ Ablon & Bogart 2017, p. 1.
- ^ Campbell-Kelly & Garcia-Swartz 2015, p. 164.
- ^ a b O'Regan 2022, p. 266.
- ^ a b c Ablon & Bogart 2017, p. 2.
- ^ Daswani & Elbayadi 2021, p. 25.
- ^ Daswani & Elbayadi 2021, pp. 26–27.
- ^ Haber & Hibbert 2018, pp. 5–6.
- ^ Kitchin & Dodge 2011, p. 37.
- ^ Tracy 2021, p. 117.
- ^ Tracy 2021, pp. 118–120.
- ^ Tracy 2021, pp. 118–119.
- ^ Kitchin & Dodge 2011, p. 26.
- ^ Tracy 2021, p. 121.
- ^ Tracy 2021, pp. 122–123.
- ^ O'Regan 2022, p. 375.
- ^ Sebesta 2012, p. 28.
- ^ Kitchin & Dodge 2011, pp. 36–37.
- ^ O'Regan 2022, pp. 394–396.
- ^ a b O'Regan 2022, p. 403.
- ^ O'Regan 2022, pp. 394, 404.
- ^ Langer 2016, pp. 44–45.
- ^ O'Regan 2022, p. 395.
- ^ Gerardo Con Díaz, "The Text in the Machine: American Copyright Law and the Many Natures of Software, 1974–1978", Technology and Culture 57 (October 2016), 753–79.
- ^ O'Regan 2022, p. 398.
- ^ O'Regan 2022, p. 399.
- ^ a b Manovich 2013, p. 333.
- ^ Jones 2014, p. 32.
- ^ Kitchin & Dodge 2011, p. iv.
- ^ a b c Jones 2014, p. xxviii.
- ^ Manovich 2013, p. 329.
Sources
- Ablon, Lillian; Bogart, Andy (2017). Zero Days, Thousands of Nights: The Life and Times of Zero-Day Vulnerabilities and Their Exploits (PDF). Rand Corporation. ISBN 978-0-8330-9761-3.
- Anderson, Thomas; Dahlin, Michael (2014). Operating Systems: Principles and Practice (2 ed.). Recursive Books. ISBN 978-0-9856735-2-9.
- Campbell-Kelly, Martin; Garcia-Swartz, Daniel D. (2015). From Mainframes to Smartphones: A History of the International Computer Industry. Harvard University Press. ISBN 978-0-674-28655-9.
- Daswani, Neil; Elbayadi, Moudy (2021). Big Breaches: Cybersecurity Lessons for Everyone. Apress. ISBN 978-1-4842-6654-0.
- Dooley, John F. (2017). Software Development, Design and Coding: With Patterns, Debugging, Unit Testing, and Refactoring. Apress. ISBN 978-1-4842-3153-1.
- Gabbrielli, Maurizio; Martini, Simone (2023). Programming Languages: Principles and Paradigms (2nd ed.). Springer. ISBN 978-3-031-34144-1.
- Galin, Daniel (2018). Software Quality: Concepts and Practice. John Wiley & Sons. ISBN 978-1-119-13449-7.
- Haber, Morey J.; Hibbert, Brad (2018). Asset Attack Vectors: Building Effective Vulnerability Management Strategies to Protect Organizations. Apress. ISBN 978-1-4842-3627-7.
- Jones, Capers (2014). The Technical and Social History of Software Engineering. Pearson Education. ISBN 978-0-321-90342-6.
- Kitchin, Rob; Dodge, Martin (2011). Code/space: Software and Everyday Life. MIT Press. ISBN 978-0-262-04248-2.
- Langer, Arthur M. (2016). Guide to Software Development: Designing and Managing the Life Cycle. Springer. ISBN 978-1-4471-6799-0.
- Manovich, Lev (2013). Software Takes Command. Bloomsbury Academic. ISBN 978-1-62356-745-3.
- O'Regan, Gerard (2022). Concise Guide to Software Engineering: From Fundamentals to Application Methods. Springer Nature. ISBN 978-3-031-07816-3.
- Osterweil, Leon J. (2013). "What Is Software? The Role of Empirical Methods in Answering the Question". Perspectives on the Future of Software Engineering: Essays in Honor of Dieter Rombach. Springer. pp. 237–254. ISBN 978-3-642-37395-4.
- Rahman, Hanif Ur; da Silva, Alberto Rodrigues; Alzayed, Asaad; Raza, Mushtaq (2024). "A Systematic Literature Review on Software Maintenance Offshoring Decisions". Information and Software Technology. 172: 107475. doi:10.1016/j.infsof.2024.107475.
- Reifer, Donald J. (2012). Software Maintenance Success Recipes. CRC Press. ISBN 978-1-4398-5167-8.
- Rosati, Pierangelo; Lynn, Theo (2020). "Measuring the Business Value of Infrastructure Migration to the Cloud". Measuring the Business Value of Cloud Computing. Springer International Publishing. pp. 19–37. ISBN 978-3-030-43198-3.
- Sebesta, Robert W. (2012). Concepts of Programming Languages (10 ed.). Addison-Wesley. ISBN 978-0-13-139531-2.
- Stull, Edward (2018). UX Fundamentals for Non-UX Professionals: User Experience Principles for Managers, Writers, Designers, and Developers. Apress. ISBN 978-1-4842-3811-0.
- Tanenbaum, Andrew S.; Bos, Herbert (2023). Modern Operating Systems, Global Edition. Pearson Higher Ed. ISBN 978-1-292-72789-9.
- Tracy, Kim W. (2021). Software: A Technical History. Morgan & Claypool Publishers. ISBN 978-1-4503-8724-8.
- Tripathy, Priyadarshi; Naik, Kshirasagar (2014). Software Evolution and Maintenance: A Practitioner's Approach. John Wiley & Sons. ISBN 978-0-470-60341-3.
- Tucker, Allen; Morelli, Ralph; de Silva, Chamindra (2011). Software Development: An Open Source Approach. CRC Press. ISBN 978-1-4398-8460-7.
- Ulziit, Bayarbuyan; Warraich, Zeeshan Akhtar; Gencel, Cigdem; Petersen, Kai (2015). "A conceptual framework of challenges and solutions for managing global software maintenance". Journal of Software: Evolution and Process. 27 (10): 763–792. doi:10.1002/smr.1720.
- Watt, Andy (2023). Building Modern SaaS Applications with C# And . NET: Build, Deploy, and Maintain Professional SaaS Applications. Packt. ISBN 978-1-80461-087-9.
- Varga, Ervin (2018). Unraveling Software Maintenance and Evolution: Thinking Outside the Box. Springer. ISBN 978-3-319-71303-8.
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