Produced by Boston-based IDG World Expo, Macworld/iWorld is a trade show with conference tracks dedicated to the Apple Macintosh platform. It was held annually in the United States during January. Macworld Expo and Macworld Conference & Exposition, the gathering dates back to 1985. Macworld is the most read Macintosh magazine in North America and a trademark of Mac Publishing, a wholly owned subsidiary of International Data Group. IDG World Expo is a subsidiary; the conference tracks require large admission fees. They last for a few more days than the Expo, which runs three or four days. Attendees can visit the exhibits, set up by hardware manufacturers and software publishers that support the Macintosh platform. On December 18, 2008, Apple announced that the 2009 Macworld Conference & Expo would be the last in which the company participates. On October 14, 2014, IDG suspended Macworld/iWorld indefinitely; the first Macworld Expo occurred in 1985 in San Francisco. The conference itself was created by Peggy Kilburn, who helped to increase the size and profit of the event during her tenure.
Among the speakers recruited by Kilburn were David Pogue, Steve Case, Bob LeVitus, as well as representatives from BMUG, LaserBoard, other major user groups. The San Francisco event has always been held at the Moscone Center; the Expo was held in Brooks Hall near the San Francisco Civic Center from 1985 until 1993, when the expansion of Moscone Center allowed the show to be consolidated in one location. Until 2005, the U. S. shows were held semiannually, with a January show in San Francisco and an additional summer show held in the Eastern US. The event was held in Boston at the Bayside Expo & Executive Conference Center expanding with a dual presence at the World Trade Center Boston. From 1998 to 2003 it took place in New York City's Jacob K. Javits Convention Center; the 2004 and 2005 summer shows, retitled Macworld Conference & Expo took place in Boston, although without Apple's participation. Other companies followed Apple's lead, canceling or reducing the size of their own exhibits, which resulted in reduced attendance compared with previous Macworld conferences.
On 16 September 2005, IDG announced that no further summertime shows would be held in NYC or in Boston. The show has taken place in other cities: A Tokyo show, produced by IDG World Expo Japan, was held at Makuhari Messe and moved to Tokyo Big Sight in 2002. Macworld Expo Summit, a version of the show targeted at U. S. government customers, was held at the Washington Convention Center in Washington, D. C. as late as 1994. In 2004, Macworld UK, part of the IDG UK division of IDG, created two Macworld Conference events on its own: one standalone conference, one conference adjoining the MacExpo trade show in London. Since 1997, the show has been known for its keynote presentations by Apple CEO Steve Jobs; the 1987 Boston MacWorld Expo was held on August 11–13. The most significant product introduction at the show was Bill Atkinson's HyperCard. More than 3,000 copies of the software were handed out. MultiFinder, Apple File Exchange, the ImageWriter LQ, EtherTalk, AppleShare PC and the AppleFax Modem were among Apple's product announcements.
Promoters estimated. MacUser's review of the show concluded positively, saying that it was "revealing and disappointing. While the Mac is becoming the business machine of choice through much of corporate America, the show didn't have the sterile atmosphere that pure business trade shows have. Most of the time it was plain outright exciting, and the promise of the future, always in the air was wholly positive." The San Francisco MacWorld had 400 exhibits. Outbound Computers demonstrated the first Macintosh-compatible portable computers at the Boston show, preceding Apple's own introduction of the PowerBook by a couple of months. MacWorld Expo took place in three locations: San Francisco, Washington DC, Boston. Apple introduced the "Power Surge" line of Power Macintosh computers at the Boston show, consisting of the Power Macintosh 8500, 7500 and 7200. In Boston, Steve Jobs gave a status report on Apple Inc. Steve was the CEO of Pixar at the time. Steve addressed some of the comments, made about Apple: "Apple has become irrelevant", "Apple can't execute anything", "Apple's culture is anarchy.
Apple's sales were $11.1 billion in 1995, $9.5 billion in 1996, about $7 billion in 1997. Steve stated; the beginning steps that Apple was going to take were: Board of Directors, Focus on Relevance, Invest in Core Assets, Meaningful Partnerships, New Product Paradigm. Steve announced the new Board of Directors: Ed Woolard and former CEO of DuPont. Steve addressed their market focus. Apple was the dominant market leader for creative professionals. 80% of all computers used in advertising, graphic design and printing were Apple computers. 64% of internet websites were created on a Macintosh. Apple was the largest education company in the world. Apple sold 60% of all computers in education, they sold over $2 billion in annual revenues. Steve said Apple's core assets were the Apple brand and Mac OS that had yet to be exploited, he said Mac OS was still the best thing in the worl
A spreadsheet is an interactive computer application for organization and storage of data in tabular form. Spreadsheets developed as computerized analogs of paper accounting worksheets; the program operates on data entered in cells of a table. Each cell may contain either numeric or text data, or the results of formulas that automatically calculate and display a value based on the contents of other cells. A spreadsheet may refer to one such electronic document. Spreadsheet users can observe the effects on calculated values; this makes the spreadsheet useful for "what-if" analysis since many cases can be investigated without manual recalculation. Modern spreadsheet software can have multiple interacting sheets, can display data either as text and numerals, or in graphical form. Besides performing basic arithmetic and mathematical functions, modern spreadsheets provide built-in functions for common financial and statistical operations; such calculations as net present value or standard deviation can be applied to tabular data with a pre-programmed function in a formula.
Spreadsheet programs provide conditional expressions, functions to convert between text and numbers, functions that operate on strings of text. Spreadsheets have replaced paper-based systems throughout the business world. Although they were first developed for accounting or bookkeeping tasks, they now are used extensively in any context where tabular lists are built and shared. LANPAR, available in 1969, was the first electronic spreadsheet on mainframe and time sharing computers. LANPAR was an acronym: LANguage for Programming Arrays at Random. VisiCalc was the first electronic spreadsheet on a microcomputer, it helped turn the Apple II computer into a popular and used system. Lotus 1-2-3 was the leading spreadsheet. Excel now has the largest market share on the Macintosh platforms. A spreadsheet program is a standard feature of an office productivity suite. Web based spreadsheets are a new category. A spreadsheet consists of a table of cells arranged into rows and columns and referred to by the X and Y locations.
X locations, the columns, are represented by letters, "A", "B", "C", etc. while rows are represented by numbers, 1, 2, 3, etc. A single cell can be referred to by addressing its column, "C10" for instance; this electronic concept of cell references was first introduced in LANPAR and a variant used in VisiCalc, known as "A1 notation". Additionally, spreadsheets have the concept of a range, a group of cells contiguous. For instance, one can refer to the first ten cells in the first column with the range "A1:A10". LANPAR innovated forward referencing/natural order calculation which didn't re-appear until Lotus 123 and Microsoft's MultiPlan Version 2. In modern spreadsheet applications, several spreadsheets known as worksheets or sheets, are gathered together to form a workbook. A workbook is physically represented by a file, containing all the data for the book, the sheets and the cells with the sheets. Worksheets are represented by tabs that flip between pages, each one containing one of the sheets, although Numbers changes this model significantly.
Cells in a multi-sheet book add the sheet name to their reference, for instance, "Sheet 1! C10"; some systems extend this syntax to allow cell references to different workbooks. Users interact with sheets through the cells. A given cell can hold data by entering it in, or a formula, created by preceding the text with an equals sign. Data might include the string of text hello world, the number 5 or the date 16-Dec-91. A formula would begin with the equals sign, =5*3, but this would be invisible because the display shows the result of the calculation, 15 in this case, not the formula itself; this may lead to confusion in some cases. The key feature of spreadsheets is the ability for a formula to refer to the contents of other cells, which may in turn be the result of a formula. To make such a formula, one replaces a number with a cell reference. For instance, the formula =5*C10 would produce the result of multiplying the value in cell C10 by the number 5. If C10 holds the value 3 the result will be 15.
But C10 might hold its own formula referring to other cells, so on. The ability to chain formulas together is. Many problems can be broken down into a series of individual mathematical steps, these can be assigned to individual formulas in cells; some of these formulas can apply to ranges as well, like the SUM function that adds up all the numbers within a range. Spreadsheets share many principles and traits of databases, but spreadsheets and databases are not the same thing. A spreadsheet is just one table, whereas a database is a collection of many tables with machine-readable semantic relationships between them. While it is true that a workbook that contains three sheets is indeed a file containing multiple tables that can interact with each other, it lacks the relational structure of a database. Spreadsheets and databases are interoperable—sheets can be imported into databases to become tables within them, database queries can be exported into spreadsheets for further analysis. A spreadsheet program is one of the main components of an office productivity suite, which also contains a word processor, a presentation program, a database management system.
Programs within a suite use similar commands for similar functions. Sharing data between the components is easier tha
A computer program is a collection of instructions that performs a specific task when executed by a computer. A computer requires programs to function. A computer program is written by a computer programmer in a programming language. From the program in its human-readable form of source code, a compiler can derive machine code—a form consisting of instructions that the computer can directly execute. Alternatively, a computer program may be executed with the aid of an interpreter. A collection of computer programs and related data are referred to as software. Computer programs may be categorized along functional lines, such as application software and system software; the underlying method used for some calculation or manipulation is known as an algorithm. The earliest programmable machines preceded the invention of the digital computer. In 1801, Joseph-Marie Jacquard devised a loom that would weave a pattern by following a series of perforated cards. Patterns could be repeated by arranging the cards.
In 1837, Charles Babbage was inspired by Jacquard's loom to attempt to build the Analytical Engine. The names of the components of the calculating device were borrowed from the textile industry. In the textile industry, yarn was brought from the store to be milled; the device would have had a "store"—memory to hold 1,000 numbers of 40 decimal digits each. Numbers from the "store" would have been transferred to the "mill", for processing, and a "thread" being the execution of programmed instructions by the device. It was programmed using two sets of perforated cards—one to direct the operation and the other for the input variables. However, after more than 17,000 pounds of the British government's money, the thousands of cogged wheels and gears never worked together. During a nine-month period in 1842–43, Ada Lovelace translated the memoir of Italian mathematician Luigi Menabrea; the memoir covered the Analytical Engine. The translation contained Note G which detailed a method for calculating Bernoulli numbers using the Analytical Engine.
This note is recognized by some historians as the world's first written computer program. In 1936, Alan Turing introduced the Universal Turing machine—a theoretical device that can model every computation that can be performed on a Turing complete computing machine, it is a finite-state machine. The machine can move the tape forth, changing its contents as it performs an algorithm; the machine starts in the initial state, goes through a sequence of steps, halts when it encounters the halt state. This machine is considered by some to be the origin of the stored-program computer—used by John von Neumann for the "Electronic Computing Instrument" that now bears the von Neumann architecture name; the Z3 computer, invented by Konrad Zuse in Germany, was a programmable computer. A digital computer uses electricity as the calculating component; the Z3 contained 2,400 relays to create the circuits. The circuits provided a floating-point, nine-instruction computer. Programming the Z3 was through a specially designed keyboard and punched tape.
The Electronic Numerical Integrator And Computer was a Turing complete, general-purpose computer that used 17,468 vacuum tubes to create the circuits. At its core, it was a series of Pascalines wired together, its 40 units weighed 30 tons, occupied 1,800 square feet, consumed $650 per hour in electricity when idle. It had 20 base-10 accumulators. Programming the ENIAC took up to two months. Three function tables needed to be rolled to fixed function panels. Function tables were connected to function panels using heavy black cables; each function table had 728 rotating knobs. Programming the ENIAC involved setting some of the 3,000 switches. Debugging a program took a week; the programmers of the ENIAC were women who were known collectively as the "ENIAC girls." The ENIAC featured parallel operations. Different sets of accumulators could work on different algorithms, it used punched card machines for input and output, it was controlled with a clock signal. It ran for eight years, calculating hydrogen bomb parameters, predicting weather patterns, producing firing tables to aim artillery guns.
The Manchester Baby was a stored-program computer. Programming transitioned away from setting dials. Only three bits of memory were available to store each instruction, so it was limited to eight instructions. 32 switches were available for programming. Computers manufactured; the computer program was written on paper for reference. An instruction was represented by a configuration of on/off settings. After setting the configuration, an execute button was pressed; this process was repeated. Computer programs were manually input via paper tape or punched cards. After the medium was loaded, the starting address was set via switches and the execute button pressed. In 1961, the Burroughs B5000 was built to be programmed in the ALGOL 60 language; the hardware featured circuits to ease the compile phase. In 1964, the IBM System/360 was a line of six computers each having the same instruction set architecture; the Model 30 was the least expensive. Customers could retain the same application software; each System/360 model featured multiprogramming.
With operating system support, multiple programs could be in memory at once. When one was waiting for input/output, another could compute; each model could emulate other computers. Customers could upgrade to the System/360 and ret
A computing platform or digital platform is the environment in which a piece of software is executed. It may be the hardware or the operating system a web browser and associated application programming interfaces, or other underlying software, as long as the program code is executed with it. Computing platforms have different abstraction levels, including a computer architecture, an OS, or runtime libraries. A computing platform is the stage. A platform can be seen both as a constraint on the software development process, in that different platforms provide different functionality and restrictions. For example, an OS may be a platform that abstracts the underlying differences in hardware and provides a generic command for saving files or accessing the network. Platforms may include: Hardware alone, in the case of small embedded systems. Embedded systems can access hardware directly, without an OS. A browser in the case of web-based software; the browser itself runs on a hardware+OS platform, but this is not relevant to software running within the browser.
An application, such as a spreadsheet or word processor, which hosts software written in an application-specific scripting language, such as an Excel macro. This can be extended to writing fully-fledged applications with the Microsoft Office suite as a platform. Software frameworks. Cloud computing and Platform as a Service. Extending the idea of a software framework, these allow application developers to build software out of components that are hosted not by the developer, but by the provider, with internet communication linking them together; the social networking sites Twitter and Facebook are considered development platforms. A virtual machine such as the Java virtual machine or. NET CLR. Applications are compiled into a format similar to machine code, known as bytecode, executed by the VM. A virtualized version of a complete system, including virtualized hardware, OS, storage; these allow, for instance, a typical Windows program to run on. Some architectures have multiple layers, with each layer acting as a platform to the one above it.
In general, a component only has to be adapted to the layer beneath it. For instance, a Java program has to be written to use the Java virtual machine and associated libraries as a platform but does not have to be adapted to run for the Windows, Linux or Macintosh OS platforms. However, the JVM, the layer beneath the application, does have to be built separately for each OS. AmigaOS, AmigaOS 4 FreeBSD, NetBSD, OpenBSD IBM i Linux Microsoft Windows OpenVMS Classic Mac OS macOS OS/2 Solaris Tru64 UNIX VM QNX z/OS Android Bada BlackBerry OS Firefox OS iOS Embedded Linux Palm OS Symbian Tizen WebOS LuneOS Windows Mobile Windows Phone Binary Runtime Environment for Wireless Cocoa Cocoa Touch Common Language Infrastructure Mono. NET Framework Silverlight Flash AIR GNU Java platform Java ME Java SE Java EE JavaFX JavaFX Mobile LiveCode Microsoft XNA Mozilla Prism, XUL and XULRunner Open Web Platform Oracle Database Qt SAP NetWeaver Shockwave Smartface Universal Windows Platform Windows Runtime Vexi Ordered from more common types to less common types: Commodity computing platforms Wintel, that is, Intel x86 or compatible personal computer hardware with Windows operating system Macintosh, custom Apple Inc. hardware and Classic Mac OS and macOS operating systems 68k-based PowerPC-based, now migrated to x86 ARM architecture based mobile devices iPhone smartphones and iPad tablet computers devices running iOS from Apple Gumstix or Raspberry Pi full function miniature computers with Linux Newton devices running the Newton OS from Apple x86 with Unix-like systems such as Linux or BSD variants CP/M computers based on the S-100 bus, maybe the earliest microcomputer platform Video game consoles, any variety 3DO Interactive Multiplayer, licensed to manufacturers Apple Pippin, a multimedia player platform for video game console development RISC processor based machines running Unix variants SPARC architecture computers running Solaris or illumos operating systems DEC Alpha cluster running OpenVMS or Tru64 UNIX Midrange computers with their custom operating systems, such as IBM OS/400 Mainframe computers with their custom operating systems, such as IBM z/OS Supercomputer architectures Cross-platform Platform virtualization Third platform Ryan Sarver: What is a platform
The Macintosh is a family of personal computers designed and sold by Apple Inc. since January 1984. The original Macintosh was the first mass-market personal computer that featured a graphical user interface, built-in screen and mouse. Apple sold the Macintosh alongside its popular Apple II family of computers for ten years before they were discontinued in 1993. Early Macintosh models were expensive, hindering its competitiveness in a market dominated by the Commodore 64 for consumers, as well as the IBM Personal Computer and its accompanying clone market for businesses. Macintosh systems still found success in education and desktop publishing and kept Apple as the second-largest PC manufacturer for the next decade. In the early 1990s, Apple introduced models such as the Macintosh LC II and Color Classic which were price-competitive with Wintel machines at the time. However, the introduction of Windows 3.1 and Intel's Pentium processor which beat the Motorola 68040 in most benchmarks took market share from Apple, by the end of 1994 Apple was relegated to third place as Compaq became the top PC manufacturer.
After the transition to the superior PowerPC-based Power Macintosh line in the mid-1990s, the falling prices of commodity PC components, poor inventory management with the Macintosh Performa, the release of Windows 95 saw the Macintosh user base decline. Prompted by the returning Steve Jobs' belief that the Macintosh line had become too complex, Apple consolidated nearly twenty models in mid-1997 down to four in mid-1999: The Power Macintosh G3, iMac, 14.1" PowerBook G3, 12" iBook. All four products were critically and commercially successful due to their high performance, competitive prices and aesthetic designs, helped return Apple to profitability. Around this time, Apple phased out the Macintosh name in favor of "Mac", a nickname, in common use since the development of the first model. Since their transition to Intel processors in 2006, the complete lineup is based on said processors and associated systems, its current lineup includes four desktops, three laptops. Its Xserve server was discontinued in 2011 in favor of the Mac Mac Pro.
Apple has developed a series of Macintosh operating systems. The first versions had no name but came to be known as the "Macintosh System Software" in 1988, "Mac OS" in 1997 with the release of Mac OS 7.6, retrospectively called "Classic Mac OS". In 2001, Apple released Mac OS X, a modern Unix-based operating system, rebranded to OS X in 2012, macOS in 2016; the current version is macOS Mojave, released on September 24, 2018. Intel-based Macs are capable of running non-Apple operating systems such as Linux, OpenBSD, Microsoft Windows with the aid of Boot Camp or third-party software. Apple produced a Unix-based operating system for the Macintosh called A/UX from 1988 to 1995, which resembled contemporary versions of the Macintosh system software. Apple does not license macOS for use on non-Apple computers, however System 7 was licensed to various companies through Apple's Macintosh clone program from 1995 to 1997. Only one company, UMAX Technologies was licensed to ship clones running Mac OS 8.
Since Apple's transition to Intel processors, there is a sizeable community around the world that specialises in hacking macOS to run on non-Apple computers, which are called "Hackintoshes". The Macintosh project began in 1979 when Jef Raskin, an Apple employee, envisioned an easy-to-use, low-cost computer for the average consumer, he wanted to name the computer after his favorite type of apple, the McIntosh, but the spelling was changed to "Macintosh" for legal reasons as the original was the same spelling as that used by McIntosh Laboratory, Inc. the audio equipment manufacturer. Steve Jobs requested that McIntosh Laboratory give Apple a release for the newly spelled name, thus allowing Apple to use it; the request was denied, forcing Apple to buy the rights to use this name. In 1978, Apple began to organize the Apple Lisa project, aiming to build a next-generation machine similar to an advanced Apple II or the yet-to-be-introduced IBM PC. In 1979, Steve Jobs learned of the advanced work on graphical user interfaces taking place at Xerox PARC.
He arranged for Apple engineers to be allowed to visit PARC to see the systems in action. The Apple Lisa project was redirected to utilize a GUI, which at that time was well beyond the state of the art for microprocessor capabilities. Things had changed with the introduction of the 32-bit Motorola 68000 in 1979, which offered at least an order of magnitude better performance than existing designs, made a software GUI machine a practical possibility; the basic layout of the Lisa was complete by 1982, at which point Jobs's continual suggestions for improvements led to him being kicked off the project. At the same time that the Lisa was becoming a GUI machine in 1979, Jef Raskin started the Macintosh project; the design at that time was for a easy-to-use machine for the average consumer. In
Lotus 1-2-3 is a discontinued spreadsheet program from Lotus Software. It was the IBM PC's first killer application, was hugely popular in the 1980s and contributed to the success of the IBM PC; the first spreadsheet, VisiCalc, had helped launch the Apple II as one of the earliest personal computers in business use. With IBM's entry into the market, VisiCalc was slow to respond, when they did, they launched what was a straight port of their existing system in spite of the expanded hardware capabilities. Lotus' solution was marketed as a three-in-one integrated solution, which handled spreadsheet calculations, database functionality, graphical charts, hence the name "1-2-3", though how much database capability was debatable given Lotus' sparse memory. 1-2-3 overtook VisiCalc, as well as Multiplan and SuperCalc, two VisiCalc competitors. 1-2-3 was the spreadsheet standard throughout the 1980s and into the 1990s, part of an unofficial set of three stand-alone office automation products that included dBase and WordPerfect, to build a complete business platform.
With the acceptance of Windows 3.0, the market for desktop software grew more. None of the major spreadsheet developers had considered the graphical user interface to supplement their DOS offerings, so they responded to Microsoft's own graphical-based products and Word. Lotus was never recovered. IBM purchased Lotus in 1995 and continued to sell Lotus offerings, only ending sales in 2013. VisiCalc was launched in 1979 on the Apple II and became a best-seller. Compared to earlier programs, VisiCalc allowed one to construct free-form calculation systems for any purpose, the limitations being memory and speed related; the application was so compelling that there were numerous stories of people buying Apple II machines to run the program. VisiCalc's runaway success on the Apple led to direct bug compatible ports to other platforms, including the Atari 8-bit family, Commodore PET and many others; this included the IBM PC when it launched in 1981, where it became another best-seller, with an estimated 300,000 sales in the first six months on the market.
There were well known problems with VisiCalc, several competitors appeared to address some of these issues. One early example was 1980's SuperCalc, which solved the problem of circular references, while a later example was Microsoft Multiplan from 1981, which offered larger sheets and other improvements. In spite of these, others, VisiCalc continued to outsell them all; the Lotus Development Corporation was founded by Mitchell Kapor, a friend of the developers of VisiCalc. 1-2-3 was written by Jonathan Sachs, who had written two spreadsheet programs while working at Concentric Data Systems, Inc. To aid its growth, in the UK, elsewhere, Lotus 1-2-3 was the first computer software to use television consumer advertising. Lotus 1-2-3 was released on 26 January 1983, overtook Visicalc in sales. Unlike Microsoft Multiplan, it stayed close to the model of VisiCalc, including the "A1" letter and number cell notation, slash-menu structure, it was cleanly programmed and bug-free, gained speed from being written in x86 assembly language and wrote directly to video memory rather than use the slow DOS and/or BIOS text output functions.
Among other novelties that Lotus introduced was a graph maker that could display several forms of graphs but required the user to have a graphics card. At this early stage, the only video boards available for the PC were IBM's Color/Graphics Adapter and Monochrome Display and Printer Adapter while the latter did not support any graphics. However, because the two video boards used different RAM and port addresses, both could be installed in the same machine and so Lotus took advantage of this by supporting a "split" screen mode whereby the user could display the worksheet portion of 1-2-3 on the sharper monochrome video and the graphics on the CGA display; the initial release of 1-2-3 supported CGA, MDA or dual monitor mode. However, a few months support was added for Hercules Computer Technology's Hercules Graphics Adapter, a clone of the MDA that allowed bitmap mode; the ability to have high-resolution text and graphics capabilities proved popular and Lotus 1-2-3 is credited with popularizing the Hercules graphics card.
Subsequent releases of Lotus 1-2-3 supported more video standards as time went on, including EGA, AT&T/Olivetti, VGA. Support for the PCjr/Tandy modes was never added and users of those machines were limited to CGA graphics; the early versions of 1-2-3 had a key disk copy protection. While the program was hard disk installable, the user had to insert the original floppy disk when starting 1-2-3 up; this protection scheme was cracked and a minor inconvenience for home users, but proved a serious nuisance in an office setting. Starting with Release 3.0, Lotus no longer used copy protection. However, it was necessary to "initialize" the System disk with one's name and company name so as to customize his copy of the program. Release 2.2 and higher had this requirement. This was an irreversible process unless one had made an exact copy of the original disk so as to be able to change names if he transferred the program to someone else; the reliance on the specific hardware of the IBM PC led to 1-2-3 being utilized as one of the two stress test applications, along w
An operating system is system software that manages computer hardware and software resources and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources. For hardware functions such as input and output and memory allocation, the operating system acts as an intermediary between programs and the computer hardware, although the application code is executed directly by the hardware and makes system calls to an OS function or is interrupted by it. Operating systems are found on many devices that contain a computer – from cellular phones and video game consoles to web servers and supercomputers; the dominant desktop operating system is Microsoft Windows with a market share of around 82.74%. MacOS by Apple Inc. is in second place, the varieties of Linux are collectively in third place. In the mobile sector, use in 2017 is up to 70% of Google's Android and according to third quarter 2016 data, Android on smartphones is dominant with 87.5 percent and a growth rate 10.3 percent per year, followed by Apple's iOS with 12.1 percent and a per year decrease in market share of 5.2 percent, while other operating systems amount to just 0.3 percent.
Linux distributions are dominant in supercomputing sectors. Other specialized classes of operating systems, such as embedded and real-time systems, exist for many applications. A single-tasking system can only run one program at a time, while a multi-tasking operating system allows more than one program to be running in concurrency; this is achieved by time-sharing, where the available processor time is divided between multiple processes. These processes are each interrupted in time slices by a task-scheduling subsystem of the operating system. Multi-tasking may be characterized in co-operative types. In preemptive multitasking, the operating system slices the CPU time and dedicates a slot to each of the programs. Unix-like operating systems, such as Solaris and Linux—as well as non-Unix-like, such as AmigaOS—support preemptive multitasking. Cooperative multitasking is achieved by relying on each process to provide time to the other processes in a defined manner. 16-bit versions of Microsoft Windows used cooperative multi-tasking.
32-bit versions of both Windows NT and Win9x, used preemptive multi-tasking. Single-user operating systems have no facilities to distinguish users, but may allow multiple programs to run in tandem. A multi-user operating system extends the basic concept of multi-tasking with facilities that identify processes and resources, such as disk space, belonging to multiple users, the system permits multiple users to interact with the system at the same time. Time-sharing operating systems schedule tasks for efficient use of the system and may include accounting software for cost allocation of processor time, mass storage and other resources to multiple users. A distributed operating system manages a group of distinct computers and makes them appear to be a single computer; the development of networked computers that could be linked and communicate with each other gave rise to distributed computing. Distributed computations are carried out on more than one machine; when computers in a group work in cooperation, they form a distributed system.
In an OS, distributed and cloud computing context, templating refers to creating a single virtual machine image as a guest operating system saving it as a tool for multiple running virtual machines. The technique is used both in virtualization and cloud computing management, is common in large server warehouses. Embedded operating systems are designed to be used in embedded computer systems, they are designed to operate on small machines like PDAs with less autonomy. They are able to operate with a limited number of resources, they are compact and efficient by design. Windows CE and Minix 3 are some examples of embedded operating systems. A real-time operating system is an operating system that guarantees to process events or data by a specific moment in time. A real-time operating system may be single- or multi-tasking, but when multitasking, it uses specialized scheduling algorithms so that a deterministic nature of behavior is achieved. An event-driven system switches between tasks based on their priorities or external events while time-sharing operating systems switch tasks based on clock interrupts.
A library operating system is one in which the services that a typical operating system provides, such as networking, are provided in the form of libraries and composed with the application and configuration code to construct a unikernel: a specialized, single address space, machine image that can be deployed to cloud or embedded environments. Early computers were built to perform a series of single tasks, like a calculator. Basic operating system features were developed in the 1950s, such as resident monitor functions that could automatically run different programs in succession to speed up processing. Operating systems did not exist in their more complex forms until the early 1960s. Hardware features were added, that enabled use of runtime libraries and parallel processing; when personal computers became popular in the 1980s, operating systems were made for them similar in concept to those used on larger computers. In the 1940s, the earliest electronic digital systems had no operating systems.
Electronic systems of this time were programmed on rows of mechanical switches or by jumper wires on plug boards. These were special-purpose systems that, for example, generated ballistics tables for the military or controlled the pri