Software

Computer software, or just software is a general term used to describe a collection of computer programs, procedures and documentation that perform some tasks on a computer system.^[1] In general sense, "software" is usually regarded as the actual computer program that is inside the computer.

Overview

Computer software are often regarded as anything but hardware, meaning that the "hard" are the parts that are tangible (able to hold) like the CPU, graphics card, keyboard^[2] while the "soft" part is the intangible objects inside the computer. Software encompasses an extremely wide array of products and technologies developed using different techniques like programming languages, scripting languages etc. The types of software include web pages developed by technologies like HTML, PHP, Perl, JSP, ASP.NET, XML, and desktop applications like Microsoft Word, OpenOffice developed by technologies like C, C++, Java, C#, etc. Software usually runs on an underlying operating system, which is a software also, like Microsoft Windows, Linux (running GNOME and KDE), Sun Solaris etc. Software also includes video games like the Super Mario Bros., Grand Theft Auto for personal computers or video game consoles.

Also a software usually runs on a software platform which can either be provided by the operating system or by operating system independent platforms like Java and .NET. Software written for one platform is usually unable to run on other platforms so that for instance, Microsoft Windows software will not be able to run on Mac OS because of the differences relating to the platforms and their own standards. These applications can work using software porting, interpreters or re-writing the source code for the specific platform.

Software includes:

Application software such as word processors which perform productive tasks for users.
Firmware which is software programmed resident to electrically programmable memory devices on board mainboards or other types of integrated hardware carriers.
Middleware which controls and co-ordinates distributed systems.
System software such as operating systems, which interface with hardware to provide the necessary services for application software.
Testware which is an umbrella term or container term for all utilities and application software that serve in combination for testing asoftware package but not necessarily may optionally contribute to operational purposes. As such, testware is not a standing configuration but merely a working environment for application software or subsets thereof.

Relationship to computer hardware

Computer software is so called to distinguish it from computer hardware, which encompasses the physical interconnections and devices required to store and execute (or run) the software. At the lowest level, software consists of a machine language specific to an individual processor. A machine language consists of groups of binary values signifying processor instructions which change the state of the computer from its preceding state. Software is an ordered sequence of instructions for changing the state of the computer hardware in a particular sequence. It is usually written in high-level programming languages that are easier and more efficient for humans to use (closer to natural language) than machine language. High-level languages are compiled or interpreted into machine language object code by the compiler so that ultimately the hardware can understand the software so that the physical computer can shut down for instance. Software may also be written in an assembly language, essentially, a mnemonic representation of a machine language using a natural language alphabet. Assembly language must be assembled into object code via an assembler.

The term "software" was first used in this sense by John W. Tukey in 1958.^[3] In computer science and software engineering, computer software is all computer programs. The theory that is the basis for most modern software was first proposed by Alan Turing in his 1935 essay Computable numbers with an application to the Entscheidungsproblem.^[4]

Types of software

File:Industrial Robotics in car production.jpg

Industrial Automation with robots engaged in vehicle assembly

Practical computer systems divide software systems into three major classes: system software, programming software and application software, although the distinction is arbitrary, and often blurred.

System software

System software helps run the computer hardware and computer system. It includes:

The purpose of systems software is to insulate the applications programmer as much as possible from the details of the particular computer complex being used, especially memory and other hardware features, and such as accessory devices as communications, printers, readers, displays, keyboards, etc.

Programming software usually provides tools to assist a programmer in writing computer programs, and software using different programming languages in a more convenient way. The tools include: + CVxx - Programming software usually provides tools to assist a programmer in writing computer programs, and software using different programming languages in a more convenient way. The tools include: +

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Application software

Application software allows end users to accomplish one or more specific (non-computer related) tasks. Typical applications include:

Businesses are probably the biggest users of application software, but almost every field of human activity now uses some form of application software.

Software topics

Architecture

Users often see things differently than programmers. People who use modern general purpose computers (as opposed to embedded systems, analog computers, supercomputers, etc.) usually see three layers of software performing a variety of tasks: platform, application, and user software.

Platform software: Platform includes the firmware, device drivers, an operating system, and typically a graphical user interface which, in total, allow a user to interact with the computer and its peripherals (associated equipment). Platform software often comes bundled with the computer. On a PC you will usually have the ability to change the platform software.
Application software: Application software or Applications are what most people think of when they think of software. Typical examples include office suites and video games. 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 almost always 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.
User-written software: End-user development tailors systems to meet users' specific needs. User software include spreadsheet templates, word processor macros, scientific simulations, and scripts for graphics and animations. Even email filters are a kind of user software. Users create this software themselves and often overlook how important it is. Depending on how competently the user-written software has been integrated into purchased application packages, many users may not be aware of the distinction between the purchased packages, and what has been added by fellow co-workers.

Documentation

Most commercial and large software have software documentation so that the end user can understand the program, what it does and how to use it. Without a clear documentation a software can be hard to use and especially if it is a very specialized and relatively complex software like the Photoshop, AutoCAD, etc.

Library

A program may not be sufficiently complete for execution by a computer. In particular, it may require additional software from a software library in order to be complete. Such a library may include software components used by stand-alone programs, but which cannot work on their own. Thus, programs may include standard routines that are common to many programs, extracted from these libraries. Libraries may also include 'stand-alone' programs which are activated by some computer event and/or perform some function (e.g., of computer 'housekeeping') but do not return data to their calling program. Libraries may be called by one to many other programs; programs may call zero to many other programs.

Maintenance

Software can be newly created or a person can be expected to develop, debug or change an existing software. Writing a software that is maintainable, which means easy to understand, develop and fix are one of the aspects of software development. There are number of rules for writing maintanable source code for the program like not writing duplicate code, code smell, spaghetti code, etc.

Execution

Computer software has to be "loaded" into the computer's storage (such as a hard drive, memory, or RAM). 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.

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. So, this is sometimes avoided by using "pointers" to data instead. 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.

Quality and reliability

Software quality is very important, especially for commercial and system software like Microsoft Office, Microsoft Windows, Linux, etc. If software is faulty (buggy), it can delete a person's work, crash the computer and do other unexpected things. Faults and errors are called "bugs". Many bugs are discovered and eliminated (debugged) 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). All major software companies, such as Microsoft, Novell and Sun Microsystems, have their own software testing departments with the specific goal of just testing. 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 quite large. For instance, NASA has extremely rigorous software testing procedures for its Space Shuttle and other programs because faulty software can crash the whole program and make the vehicle not functional, at great expense.

License

The software's license gives the user the right to use the software in the licensed environment. Some software comes with the license when purchased off the shelf, or an OEM license when bundled with hardware. Other software comes with a free software license, granting the recipient the rights to modify and redistribute the software. Software can also be in the form of freeware or shareware. See also License Management.

Patents

Software can be patented; however software patents can be controversial in the software industry with many people holding different views about it. Some believe that they hinder software development, while others argue that software patents provide an important incentive to spur software innovation. See software patent debate. The controversy over software patents is that a specific algorithm or technique that the software has cannot be duplicated by others and is considered an intellectual property and copyright infringement depending on the severity.

Ethics and rights

There is more than one approach to creating, licensing, and distributing software. For instance, the free software or the open source community produces software under licensing that makes it free for inspection of its code, modification of its code, and distribution. While the software released under an open source license (such as General Public License, or GPL for short) can be sold for money^[5], the distribution cannot be restricted in the same way as software with copyright and patent restrictions (used by corporations to require licensing fees).

While some advocates of free software use slogans such as "information wants to be free," hinting that it is easy to copy digital data and that the licenses (enforced through laws) are unnatural restrictions, other creators and users of open source software recognize it to be one model among many for software creation, licensing, and distribution. And the laws themselves are put into place for the ostensible purpose of increasing creative output, by allowing the creators to control and profit most effectively from their intellectual property.

Implementation

Before a software is created, the creator (programmer/coder/writer/developer) usually figures out what kind of software he/she wants to create for instance whether it be webpage, desktop application, computer games, etc. Then he/she usually picks a computer language that is usually used for creating that specific software. For instance, PHP, HTML and ASP.NET (using C# and VB.NET) are particularly well suited for designing webpages, while C++ and C programming language are more well suited for designing system software like Microsoft Windows, Linux, etc. If a person decides to use C programming language to write the source code, the person is expected to follow the C programming language explicitly defined programming syntax. Otherwise, the C programming language compiler will produce an error and can't compile the program to make it a machine code in a binary file. Individual programming language has its own individual compiler that knows only how to understand (parse) the source code only written for that programming language. In other words, a person cannot expect a program written in C++ be compiled and running through a Java programming language compiler and vice versa.

Then software is usually created (coded/written/programmed) and designed in integrated development environments (IDE) like emacs, xemacs, Microsoft Visual Studio and Eclipse that can simplify the process and compile the specific programming language that the programmer had used. Then the software developer debugs the software usually through a debugger to eliminate the compile-time and/or run-time error so that the software works like how he/she expects.

As noted in different section, software is usually created on top of an existing software and the application programming interface (API) that the underlying software provides like GTK+, JavaBeans, Swing etc. Libraries (APIs) are categorized for different purposes. For instance JavaBeans library is used for designing enterprise applications, Windows Forms library is used for designing graphical user interface (GUI) applications like Microsoft Word and Windows Communication Foundation is used for designing web services. There are also underlying concepts in computer programming like quicksort, hashtable, array, binary tree that can be useful to creating a software. When a program is designed, it relies on the API. For instance, if a user is designing a Microsoft Windows desktop application, he/she might use the .NET Windows Forms library to design the desktop application and call its APIs like Form1.Close() and Form1.Show() to close or open the application and write the additional operations him/herself that it need to have. Without these APIs, the programmer needs to write these APIs him/herself. Companies like Sun Microsystems, Novell and Microsoft provide their own APIs so that many applications are written using their software libraries that usually have numerous APIs in them.

Software has special economic characteristics that make its design, creation, and distribution different from most other economic goods.^[6]^[7]

Industry and organizations

There are many software companies in the world and selling software can be quite profitable industry. For instance, Bill Gates, the founder of Microsoft is the second richest man in the world in 2008 largely by selling the Microsoft Windows and Microsoft Office software programs, and same goes for Larry Ellison largely through his Oracle database software.

There are many non-profit software organizations like the Free Software Foundation, GNU Project, Mozilla Foundation. Also there are many software standards organizations like the W3C and others that try to come up with a software standard so that many software can work and interoperate with each other like through standards such as XML, HTML, HTTP, FTP, etc.

Some large software companies include Microsoft, IBM, Oracle, SAP and HP.^[8]

References

^ "Wordreference.com: WordNet 2.0". Princeton University, Princeton, NJ. Retrieved 2007-08-19.
^ software..(n.d.). Dictionary.com Unabridged (v 1.1). Retrieved 2007-04-13, from Dictionary.com website: http://dictionary.reference.com/browse/software
^ "John Tukey, 85, Statistician; Coined the Word 'Software'". New York Times. 2000-07-28. {{cite news}}: Check date values in: |date= (help)
^ Hally, Mike (2005:79). Electronic brains/Stories from the dawn of the computer age. British Broadcasting Corporation and Granta Books, London. ISBN 1-86207-663-4.
^ GNU project: "Selling Free Software": "we encourage people who redistribute free software to charge as much as they wish or can."
^ v. Engelhardt, Sebastian (2008): "The Economic Properties of Software", Jena Economic Research Papers, Volume 2 (2008), Number 2008-045. (in Adobe pdf format)
^ "Why Open Source Is The Optimum Economic Paradigm for Software" by Dan Kaminsky 1999
^ "Software Top 100: the world's largest software companies". the Top 100 research foundation. Retrieved 2008-04-28.

[1] "Wordreference.com: WordNet 2.0". Princeton University, Princeton, NJ. Retrieved 2007-08-19.

[2] software..(n.d.). Dictionary.com Unabridged (v 1.1). Retrieved 2007-04-13, from Dictionary.com website: http://dictionary.reference.com/browse/software

[3] "John Tukey, 85, Statistician; Coined the Word 'Software'". New York Times. 2000-07-28. {{cite news}}: Check date values in: |date= (help)

[4] Hally, Mike (2005:79). Electronic brains/Stories from the dawn of the computer age. British Broadcasting Corporation and Granta Books, London. ISBN 1-86207-663-4.

[5] GNU project: "Selling Free Software": "we encourage people who redistribute free software to charge as much as they wish or can."

[6] v. Engelhardt, Sebastian (2008): "The Economic Properties of Software", Jena Economic Research Papers, Volume 2 (2008), Number 2008-045. (in Adobe pdf format)

[7] "Why Open Source Is The Optimum Economic Paradigm for Software" by Dan Kaminsky 1999

[8] "Software Top 100: the world's largest software companies". the Top 100 research foundation. Retrieved 2008-04-28.

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v t e Software distribution
Licenses	Beerware Floating licensing Free and open-source Free Open source Freely redistributable License-free Proprietary Public domain Source-available
Compensation models	Adware Commercial software Retail software Crippleware Crowdfunding Freemium Freeware Pay what you want Careware Donationware Open-core model Postcardware Shareware Nagware Trialware
Delivery methods	Digital distribution File sharing On-premises Pre-installed Product bundling Retail software Sneakernet Software as a service
Deceptive and/or illicit	Unwanted software bundling Malware Infostealer Ransomware Spyware Trojan horse Worm Scareware Shovelware
Software release life cycle	Abandonware End-of-life Long-term support Software maintenance Software maintainer Software publisher Vaporware list
Copy protection	Digital rights management Software protection dongle License manager Product activation Product key Software copyright Software license server Software patent Torrent poisoning