X86 is a family of instruction set architectures based on the Intel 8086 microprocessor and its 8088 variant. The 8086 was introduced in 1978 as a 16-bit extension of Intel's 8-bit 8080 microprocessor, with memory segmentation as a solution for addressing more memory than can be covered by a plain 16-bit address; the term "x86" came into being because the names of several successors to Intel's 8086 processor end in "86", including the 80186, 80286, 80386 and 80486 processors. Many additions and extensions have been added to the x86 instruction set over the years consistently with full backward compatibility; the architecture has been implemented in processors from Intel, Cyrix, AMD, VIA and many other companies. Of those, only Intel, AMD, VIA hold x86 architectural licenses, are producing modern 64-bit designs; the term is not synonymous with IBM PC compatibility, as this implies a multitude of other computer hardware. As of 2018, the majority of personal computers and laptops sold are based on the x86 architecture, while other categories—especially high-volume mobile categories such as smartphones or tablets—are dominated by ARM.
In the 1980s and early 1990s, when the 8088 and 80286 were still in common use, the term x86 represented any 8086 compatible CPU. Today, however, x86 implies a binary compatibility with the 32-bit instruction set of the 80386; this is due to the fact that this instruction set has become something of a lowest common denominator for many modern operating systems and also because the term became common after the introduction of the 80386 in 1985. A few years after the introduction of the 8086 and 8088, Intel added some complexity to its naming scheme and terminology as the "iAPX" of the ambitious but ill-fated Intel iAPX 432 processor was tried on the more successful 8086 family of chips, applied as a kind of system-level prefix. An 8086 system, including coprocessors such as 8087 and 8089, as well as simpler Intel-specific system chips, was thereby described as an iAPX 86 system. There were terms iRMX, iSBC, iSBX – all together under the heading Microsystem 80. However, this naming scheme was quite temporary.
Although the 8086 was developed for embedded systems and small multi-user or single-user computers as a response to the successful 8080-compatible Zilog Z80, the x86 line soon grew in features and processing power. Today, x86 is ubiquitous in both stationary and portable personal computers, is used in midrange computers, workstations and most new supercomputer clusters of the TOP500 list. A large amount of software, including a large list of x86 operating systems are using x86-based hardware. Modern x86 is uncommon in embedded systems and small low power applications as well as low-cost microprocessor markets, such as home appliances and toys, lack any significant x86 presence. Simple 8-bit and 16-bit based architectures are common here, although the x86-compatible VIA C7, VIA Nano, AMD's Geode, Athlon Neo and Intel Atom are examples of 32- and 64-bit designs used in some low power and low cost segments. There have been several attempts, including by Intel itself, to end the market dominance of the "inelegant" x86 architecture designed directly from the first simple 8-bit microprocessors.
Examples of this are the iAPX 432, the Intel 960, Intel 860 and the Intel/Hewlett-Packard Itanium architecture. However, the continuous refinement of x86 microarchitectures and semiconductor manufacturing would make it hard to replace x86 in many segments. AMD's 64-bit extension of x86 and the scalability of x86 chips such as the eight-core Intel Xeon and 12-core AMD Opteron is underlining x86 as an example of how continuous refinement of established industry standards can resist the competition from new architectures; the table below lists processor models and model series implementing variations of the x86 instruction set, in chronological order. Each line item is characterized by improved or commercially successful processor microarchitecture designs. At various times, companies such as IBM, NEC, AMD, TI, STM, Fujitsu, OKI, Cyrix, Intersil, C&T, NexGen, UMC, DM&P started to design or manufacture x86 processors intended for personal computers as well as embedded systems; such x86 implementations are simple copies but employ different internal microarchitectures as well as different solutions at the electronic and physical levels.
Quite early compatible microprocessors were 16-bit, while 32-bit designs were developed much later. For the personal computer market, real quantities started to appear around 1990 with i386 and i486 compatible processors named to Intel's original chips. Other companies, which designed or manufactured x86 or x87 processors, include ITT Corporation, National Semiconductor, ULSI System Technology, Weitek. Following the pipelined i486, Intel introduced the Pentium brand name for their new set of superscalar x86 designs.
MS-DOS is an operating system for x86-based personal computers developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, some operating systems attempting to be compatible with MS-DOS, are sometimes referred to as "DOS". MS-DOS was the main operating system for IBM PC compatible personal computers during the 1980s and the early 1990s, when it was superseded by operating systems offering a graphical user interface, in various generations of the graphical Microsoft Windows operating system. MS-DOS was the result of the language developed in the seventies, used by IBM for its mainframe operating system. Microsoft acquired the rights to meet IBM specifications. IBM re-released it on August 12, 1981 as PC DOS 1.0 for use in their PCs. Although MS-DOS and PC DOS were developed in parallel by Microsoft and IBM, the two products diverged after twelve years, in 1993, with recognizable differences in compatibility and capabilities. During its lifetime, several competing products were released for the x86 platform, MS-DOS went through eight versions, until development ceased in 2000.
MS-DOS was targeted at Intel 8086 processors running on computer hardware using floppy disks to store and access not only the operating system, but application software and user data as well. Progressive version releases delivered support for other mass storage media in greater sizes and formats, along with added feature support for newer processors and evolving computer architectures, it was the key product in Microsoft's growth from a programming language company to a diverse software development firm, providing the company with essential revenue and marketing resources. It was the underlying basic operating system on which early versions of Windows ran as a GUI, it is a flexible operating system, consumes negligible installation space. MS-DOS was a renamed form of 86-DOS – owned by Seattle Computer Products, written by Tim Paterson. Development of 86-DOS took only six weeks, as it was a clone of Digital Research's CP/M, ported to run on 8086 processors and with two notable differences compared to CP/M.
This first version was shipped in August 1980. Microsoft, which needed an operating system for the IBM Personal Computer hired Tim Paterson in May 1981 and bought 86-DOS 1.10 for $75,000 in July of the same year. Microsoft kept the version number, but renamed it MS-DOS, they licensed MS-DOS 1.10/1.14 to IBM, who, in August 1981, offered it as PC DOS 1.0 as one of three operating systems for the IBM 5150, or the IBM PC. Within a year Microsoft licensed MS-DOS to over 70 other companies, it was designed to be an OS. Each computer would have its own distinct hardware and its own version of MS-DOS, similar to the situation that existed for CP/M, with MS-DOS emulating the same solution as CP/M to adapt for different hardware platforms. To this end, MS-DOS was designed with a modular structure with internal device drivers, minimally for primary disk drives and the console, integrated with the kernel and loaded by the boot loader, installable device drivers for other devices loaded and integrated at boot time.
The OEM would use a development kit provided by Microsoft to build a version of MS-DOS with their basic I/O drivers and a standard Microsoft kernel, which they would supply on disk to end users along with the hardware. Thus, there were many different versions of "MS-DOS" for different hardware, there is a major distinction between an IBM-compatible machine and an MS-DOS machine; some machines, like the Tandy 2000, were MS-DOS compatible but not IBM-compatible, so they could run software written for MS-DOS without dependence on the peripheral hardware of the IBM PC architecture. This design would have worked well for compatibility, if application programs had only used MS-DOS services to perform device I/O, indeed the same design philosophy is embodied in Windows NT. However, in MS-DOS's early days, the greater speed attainable by programs through direct control of hardware was of particular importance for games, which pushed the limits of their contemporary hardware. Soon an IBM-compatible architecture became the goal, before long all 8086-family computers emulated IBM's hardware, only a single version of MS-DOS for a fixed hardware platform was needed for the market.
This version is the version of MS-DOS, discussed here, as the dozens of other OEM versions of "MS-DOS" were only relevant to the systems they were designed for, in any case were similar in function and capability to some standard version for the IBM PC—often the same-numbered version, but not always, since some OEMs used their own proprietary version numbering schemes —with a few notable exceptions. Microsoft omitted multi-user support from MS-DOS because Microsoft's Unix-based operating system, was multi-user; the company planned, over time, to improve MS-DOS so it would be indistinguishable from single-user Xenix, or XEDOS, which would run on the Motorola 68000, Zilog Z8000, the LSI-11. Microsoft advertised MS-DOS and Xenix together, listing the shared features of its "single-user OS" and "the multi-user, multi-tasking, UNIX-derived operating system", promising easy
Microsoft Corporation is an American multinational technology company with headquarters in Redmond, Washington. It develops, licenses and sells computer software, consumer electronics, personal computers, related services, its best known software products are the Microsoft Windows line of operating systems, the Microsoft Office suite, the Internet Explorer and Edge web browsers. Its flagship hardware products are the Xbox video game consoles and the Microsoft Surface lineup of touchscreen personal computers; as of 2016, it is the world's largest software maker by revenue, one of the world's most valuable companies. The word "Microsoft" is a portmanteau of "microcomputer" and "software". Microsoft is ranked No. 30 in the 2018 Fortune 500 rankings of the largest United States corporations by total revenue. Microsoft was founded by Bill Gates and Paul Allen on April 4, 1975, to develop and sell BASIC interpreters for the Altair 8800, it rose to dominate the personal computer operating system market with MS-DOS in the mid-1980s, followed by Microsoft Windows.
The company's 1986 initial public offering, subsequent rise in its share price, created three billionaires and an estimated 12,000 millionaires among Microsoft employees. Since the 1990s, it has diversified from the operating system market and has made a number of corporate acquisitions, their largest being the acquisition of LinkedIn for $26.2 billion in December 2016, followed by their acquisition of Skype Technologies for $8.5 billion in May 2011. As of 2015, Microsoft is market-dominant in the IBM PC-compatible operating system market and the office software suite market, although it has lost the majority of the overall operating system market to Android; the company produces a wide range of other consumer and enterprise software for desktops and servers, including Internet search, the digital services market, mixed reality, cloud computing and software development. Steve Ballmer replaced Gates as CEO in 2000, envisioned a "devices and services" strategy; this began with the acquisition of Danger Inc. in 2008, entering the personal computer production market for the first time in June 2012 with the launch of the Microsoft Surface line of tablet computers.
Since Satya Nadella took over as CEO in 2014, the company has scaled back on hardware and has instead focused on cloud computing, a move that helped the company's shares reach its highest value since December 1999. In 2018, Microsoft surpassed Apple as the most valuable publicly traded company in the world after being dethroned by the tech giant in 2010. Childhood friends Bill Gates and Paul Allen sought to make a business utilizing their shared skills in computer programming. In 1972 they founded their first company, named Traf-O-Data, which sold a rudimentary computer to track and analyze automobile traffic data. While Gates enrolled at Harvard, Allen pursued a degree in computer science at Washington State University, though he dropped out of school to work at Honeywell; the January 1975 issue of Popular Electronics featured Micro Instrumentation and Telemetry Systems's Altair 8800 microcomputer, which inspired Allen to suggest that they could program a BASIC interpreter for the device. After a call from Gates claiming to have a working interpreter, MITS requested a demonstration.
Since they didn't yet have one, Allen worked on a simulator for the Altair while Gates developed the interpreter. Although they developed the interpreter on a simulator and not the actual device, it worked flawlessly when they demonstrated the interpreter to MITS in Albuquerque, New Mexico. MITS agreed to distribute it, marketing it as Altair BASIC. Gates and Allen established Microsoft on April 4, 1975, with Gates as the CEO; the original name of "Micro-Soft" was suggested by Allen. In August 1977 the company formed an agreement with ASCII Magazine in Japan, resulting in its first international office, "ASCII Microsoft". Microsoft moved to a new home in Bellevue, Washington in January 1979. Microsoft entered the operating system business in 1980 with its own version of Unix, called Xenix. However, it was MS-DOS. After negotiations with Digital Research failed, IBM awarded a contract to Microsoft in November 1980 to provide a version of the CP/M OS, set to be used in the upcoming IBM Personal Computer.
For this deal, Microsoft purchased a CP/M clone called 86-DOS from Seattle Computer Products, which it branded as MS-DOS, though IBM rebranded it to PC DOS. Following the release of the IBM PC in August 1981, Microsoft retained ownership of MS-DOS. Since IBM had copyrighted the IBM PC BIOS, other companies had to reverse engineer it in order for non-IBM hardware to run as IBM PC compatibles, but no such restriction applied to the operating systems. Due to various factors, such as MS-DOS's available software selection, Microsoft became the leading PC operating systems vendor; the company expanded into new markets with the release of the Microsoft Mouse in 1983, as well as with a publishing division named Microsoft Press. Paul Allen resigned from Microsoft in 1983 after developing Hodgkin's disease. Allen claimed that Gates wanted to dilute his share in the company when he was diagnosed with Hodgkin's disease because he didn't think he was working hard enough. After leaving Microsoft, Allen lost billions of dollars on ill-conceived or mistimed technology investments.
He invested in low-tech sectors, sports teams, commercial real estate. Despite having begun jointly developing a new operating system, OS/2, with IBM in
Quarterdeck Expanded Memory Manager is a memory manager produced by Quarterdeck Office Systems in the late 1980s through late 1990s. It was the most popular third-party memory manager for the MS-DOS and other DOS operating systems. QRAM A memory manager for Intel 80286 or higher CPUs, it supports Technologies chipsets. 2.02 added. QEXT now reallocates eXtended Memory Specification, it includes VIDRAM, Optimize, LOADHI from QEMM 6.02, Manifest 1.13. Earlier versions of QRAM supported the older 8086 and 8088 CPUs. QEMM Game Edition It is a version of QEMM. Patches for regular QEMM do not work on QEMM Game Edition. QEMM MegaBundle In the version shipped with Borland SideKick for Windows, it is a version with SideBar 1.00 and QEMM 7.5. DESQview 386 It includes DESQview and QEMM-386. QEMM provides access to the Upper Memory Area and memory through the Expanded Memory Specification, Extended Memory Specification, Virtual Control Program Interface and DOS Protected Mode Interface. Quickboot: It allows a form of warm reboot or local reboot to be performed without going through the BIOS.
It will therefore bypass the POST, including the BIOS startup screen and the time-consuming memory test and device enumeration, just restore the CPU state and interrupts to their initial state after POST. It relocates DOS kernel, COMMAND. COM interpreter, DOS resources, it supports higher. It allows drivers to be loaded before loading QEMM and still allow the use of QEMM's Stealth feature, it was a virtual memory compression utility for Windows 3.1, Windows For Workgroups and Windows 95. MagnaRAM is included with QEMM 97. MagnaRAM was released as a separate utility. MagnaRAM worked by replacing a portion of Windows' virtual memory system. MagnaRAM would insert itself in the string of Windows Programs that determined what pieces of RAM will be moved to the hard disk. Instead of writing directly to the hard disk, the information to be written would go to MagnaRAM's own buffer as this was a faster process. During CPU idle, MagnaRAM would compress the information in its own RAM buffer; when the RAM buffer becomes full, it is swapped to the hard disk taking both less time and less space.
First released in 1990-01-11, Manifest is a hardware information utility that displays information about user's system. 1.11 fixed minor cosmetic bugs. 1.12 can identify PS/2 Model 57SX, Compaq Deskpro 486s/16M, Sharp MZ-100. Available EMS in System Overview screen was corrected. 1.13 fixed Award BIOS identification problem. Version 2.0 provides information on network, enhance reporting of video capabilities, APM, DPMI/VCPI/EMS/XMS memory. New feature include editing Windows boot configuration files. Similar to MEMMAKER, it is a utility that calculates, allows user to choose optimal orders of loading drivers and TSRs. However, OPTIMIZE allows preview of adjustments be made without rebooting, it was first release in 1990-01-11. It is shipped with DESQview. QDPMI is a DPMI 0.9 server driver, authored by Dan Spear. It requires 386 CPU and QEMM386, it is a version of QEMM driver for IBM PS/2 Model 50 and 60. Version 4.03 supports IBM Memory Expansion Option boards with 2-8MB memory. It can relocate memory assigned for CGA character set away from UMA.
Beginning with QEMM version 8, it allows ROM contents in UMA to be relocated to provide more memory for TSRs. Additional Stealth Windows compatibility is provided with VxDs. Stealth D * Space allows DriveSpace to be loaded high, it allows Toshiba laptops to work with QEMM's EMS manager. First released in 1990-01-10, it can provide extra conventional memory in text mode programs, by reclaiming buffers located in UMA that are used in graphics modes, it requires EGA/VGA-compatible video card. VIDRAMEMS supports DMA-based video memory access at the expense of EMS memory for buffer. LOADHI. SYS loads up to 1 device driver at a time in QEMM 4.23, 2 in QEMM 5, 32 in QEMM 6. Maximum compression threshold setting is 100% for all versions of MagnaRAM 2.00-2.02, except for MagnaRAM 2.00 included with QEMM 8.00, which has the maximum setting of 80%. QEMM 5.0 can manage up to 16 MB EMS, 16 MB XMS. QEMM 6.0 can manage up to 64 MB EMS, 64 MB XMS. QEMM 6.02 can manage up to 128 MB EMS, 128 MB XMS. EMBMEM parameter limit was removed.
QEMM 7.0-7.03 can manage up to 128 MB EMS, 128 MB XMS. QEMM 7.04, 7.5, 8.0-8.3 and 97 can manage up to 256 MB EMS/XMS. By default, QEMM 7.04 and above provide up to a total of 64 MB RAM shared among XMS, EMS and VCPI memory, unless the USERAM= parameter is used. For example, to allow access to up to 256 MB EMS, specify: QEMM386. SYS USERAM=1M-256M For QEMM 7.04 and above, the maximum addressable RAM is 256 MB of memory, shared among XMS, EMS and VCPI memory. XMS allocates the entire 256 MB and shares it with EMS and VCPI as needed, that is, as EMS and VCPI request memory blocks, XMS free memory is reduced by that same amount. Versions up to QEMM 6.01 can process batch files up to 9KB, 20KB in QEMM 6.02. Batch file line limit is 512 for QEMM versions up to 6.02. Stealth D*Space does not support Windows 95 or versions of DriveSpace; the product was called QEMM-386, was released with a complementary product called QRAM. The 386 suffix was dropped starting with QEMM version 7.0 in 1993, when Intel released the Intel Pentium on 3/22/1993.
The final release was re-branded as QEMM 97 to follow Microsoft's new branding trend of using year released instead of version numbers Windows 95 and Windows 95 OSR2. Supported intel 80386 and DOS 3.30. Bundled with QRAM for 80286 or
A command-line interface or command language interpreter known as command-line user interface, console user interface and character user interface, is a means of interacting with a computer program where the user issues commands to the program in the form of successive lines of text. A program which handles the interface is called shell; the CLI was the primary means of interaction with most computer systems on computer terminals in the mid-1960s, continued to be used throughout the 1970s and 1980s on OpenVMS, Unix systems and personal computer systems including MS-DOS, CP/M and Apple DOS. The interface is implemented with a command line shell, a program that accepts commands as text input and converts commands into appropriate operating system functions. Today, many end users if use command-line interfaces and instead rely upon graphical user interfaces and menu-driven interactions. However, many software developers, system administrators and advanced users still rely on command-line interfaces to perform tasks more efficiently, configure their machine, or access programs and program features that are not available through a graphical interface.
Alternatives to the command line include, but are not limited to text user interface menus, keyboard shortcuts, various other desktop metaphors centered on the pointer. Examples of this include the Windows versions 1, 2, 3, 3.1, 3.11, DosShell, Mouse Systems PowerPanel. Programs with command-line interfaces are easier to automate via scripting. Command-line interfaces for software other than operating systems include a number of programming languages such as Tcl/Tk, PHP, others, as well as utilities such as the compression utility WinZip, some FTP and SSH/Telnet clients. Compared with a graphical user interface, a command line requires fewer system resources to implement. Since options to commands are given in a few characters in each command line, an experienced user finds the options easier to access. Automation of repetitive tasks is simplified - most operating systems using a command line interface support some mechanism for storing used sequences in a disk file, for re-use. A command-line history can be kept, allowing repetition of commands.
A command-line system may require paper or online manuals for the user's reference, although a "help" option provides a concise review of the options of a command. The command-line environment may not provide the graphical enhancements such as different fonts or extended edit windows found in a GUI, it may be difficult for a new user to become familiar with all the commands and options available, compared with the drop-down menus of a graphical user interface, without repeated reference to manuals. Operating system command line interfaces are distinct programs supplied with the operating system. A program that implements such a text interface is called a command-line interpreter, command processor or shell. Examples of command-line interpreters include DEC's DIGITAL Command Language in OpenVMS and RSX-11, the various Unix shells, CP/M's CCP, DOS's COMMAND. COM, as well as the OS/2 and the Windows CMD. EXE programs, the latter groups being based on DEC's RSX-11 and RSTS CLIs. Under most operating systems, it is possible to replace the default shell program with alternatives.
Although the term'shell' is used to describe a command-line interpreter speaking a'shell' can be any program that constitutes the user-interface, including graphically oriented ones. For example, the default Windows GUI is a shell program named EXPLORER. EXE, as defined in the SHELL=EXPLORER. EXE line in the WIN. INI configuration file; these programs are shells, but not CLIs. Application programs may have command line interfaces. An application program may support none, any, or all of these three major types of command line interface mechanisms: Parameters: Most operating systems support a means to pass additional information to a program when it is launched; when a program is launched from an OS command line shell, additional text provided along with the program name is passed to the launched program. Interactive command line sessions: After launch, a program may provide an operator with an independent means to enter commands in the form of text. OS inter-process communication: Most operating systems support means of inter-process communication.
Command lines from client processes may be redirected to a CLI program by one of these methods. Some applications support only a CLI, presenting a CLI prompt to the user and acting upon command lines as they are entered. Other programs support both a CLI and a GUI. In some cases, a GUI is a wrapper around a separate CLI executable file. In other cases, a program may provide a CLI as an optional alternative to its GUI. CLIs and GUIs support different functionality. For example, all features of MATLAB, a numerical analysis computer program, are available via the CLI, whereas the MATLAB GUI exposes only a subset of features; the early Sierra games, such as the first three King's Quest games, used commands from an internal command line to move the character around in the graphic window. The command-line interface evolved from a form of dialog once conducted by humans over teleprinter machines, in which human operators remotely exchanged inf
Microsoft Windows is a group of several graphical operating system families, all of which are developed and sold by Microsoft. Each family caters to a certain sector of the computing industry. Active Windows families include Windows Embedded. Defunct Windows families include Windows Mobile and Windows Phone. Microsoft introduced an operating environment named Windows on November 20, 1985, as a graphical operating system shell for MS-DOS in response to the growing interest in graphical user interfaces. Microsoft Windows came to dominate the world's personal computer market with over 90% market share, overtaking Mac OS, introduced in 1984. Apple came to see Windows as an unfair encroachment on their innovation in GUI development as implemented on products such as the Lisa and Macintosh. On PCs, Windows is still the most popular operating system. However, in 2014, Microsoft admitted losing the majority of the overall operating system market to Android, because of the massive growth in sales of Android smartphones.
In 2014, the number of Windows devices sold was less than 25 %. This comparison however may not be relevant, as the two operating systems traditionally target different platforms. Still, numbers for server use of Windows show one third market share, similar to that for end user use; as of October 2018, the most recent version of Windows for PCs, tablets and embedded devices is Windows 10. The most recent versions for server computers is Windows Server 2019. A specialized version of Windows runs on the Xbox One video game console. Microsoft, the developer of Windows, has registered several trademarks, each of which denote a family of Windows operating systems that target a specific sector of the computing industry; as of 2014, the following Windows families are being developed: Windows NT: Started as a family of operating systems with Windows NT 3.1, an operating system for server computers and workstations. It now consists of three operating system subfamilies that are released at the same time and share the same kernel: Windows: The operating system for mainstream personal computers and smartphones.
The latest version is Windows 10. The main competitor of this family is macOS by Apple for personal computers and Android for mobile devices. Windows Server: The operating system for server computers; the latest version is Windows Server 2019. Unlike its client sibling, it has adopted a strong naming scheme; the main competitor of this family is Linux. Windows PE: A lightweight version of its Windows sibling, meant to operate as a live operating system, used for installing Windows on bare-metal computers, recovery or troubleshooting purposes; the latest version is Windows PE 10. Windows IoT: Initially, Microsoft developed Windows CE as a general-purpose operating system for every device, too resource-limited to be called a full-fledged computer. However, Windows CE was renamed Windows Embedded Compact and was folded under Windows Compact trademark which consists of Windows Embedded Industry, Windows Embedded Professional, Windows Embedded Standard, Windows Embedded Handheld and Windows Embedded Automotive.
The following Windows families are no longer being developed: Windows 9x: An operating system that targeted consumers market. Discontinued because of suboptimal performance. Microsoft now caters to the consumer market with Windows NT. Windows Mobile: The predecessor to Windows Phone, it was a mobile phone operating system; the first version was called Pocket PC 2000. The last version is Windows Mobile 6.5. Windows Phone: An operating system sold only to manufacturers of smartphones; the first version was Windows Phone 7, followed by Windows Phone 8, the last version Windows Phone 8.1. It was succeeded by Windows 10 Mobile; the term Windows collectively describes any or all of several generations of Microsoft operating system products. These products are categorized as follows: The history of Windows dates back to 1981, when Microsoft started work on a program called "Interface Manager", it was announced in November 1983 under the name "Windows", but Windows 1.0 was not released until November 1985.
Windows 1.0 was to achieved little popularity. Windows 1.0 is not a complete operating system. The shell of Windows 1.0 is a program known as the MS-DOS Executive. Components included Calculator, Cardfile, Clipboard viewer, Control Panel, Paint, Reversi and Write. Windows 1.0 does not allow overlapping windows. Instead all windows are tiled. Only modal dialog boxes may appear over other windows. Microsoft sold as included Windows Development libraries with the C development environment, which included numerous windows samples. Windows 2.0 was released in December 1987, was more popular than its predecessor. It features several improvements to the user memory management. Windows 2.03 changed the OS from tiled windows to overlapping windows. The result of this change led to Apple Computer filing a suit against Microsoft alleging infringement on Apple's copyrights. Windows 2.0
GNU General Public License
The GNU General Public License is a widely-used free software license, which guarantees end users the freedom to run, study and modify the software. The license was written by Richard Stallman of the Free Software Foundation for the GNU Project, grants the recipients of a computer program the rights of the Free Software Definition; the GPL is a copyleft license, which means that derivative work can only be distributed under the same license terms. This is in distinction to permissive free software licenses, of which the BSD licenses and the MIT License are widely-used examples. GPL was the first copyleft license for general use; the GPL license family has been one of the most popular software licenses in the free and open-source software domain. Prominent free-software programs licensed under the GPL include the Linux kernel and the GNU Compiler Collection. David A. Wheeler argues that the copyleft provided by the GPL was crucial to the success of Linux-based systems, giving the programmers who contributed to the kernel the assurance that their work would benefit the whole world and remain free, rather than being exploited by software companies that would not have to give anything back to the community.
In 2007, the third version of the license was released to address some perceived problems with the second version that were discovered during its long-time usage. To keep the license up to date, the GPL license includes an optional "any version" clause, allowing users to choose between the original terms or the terms in new versions as updated by the FSF. Developers can omit it; the GPL was written by Richard Stallman in 1989, for use with programs released as part of the GNU project. The original GPL was based on a unification of similar licenses used for early versions of GNU Emacs, the GNU Debugger and the GNU C Compiler; these licenses contained similar provisions to the modern GPL, but were specific to each program, rendering them incompatible, despite being the same license. Stallman's goal was to produce one license that could be used for any project, thus making it possible for many projects to share code; the second version of the license, version 2, was released in 1991. Over the following 15 years, members of the free software community became concerned over problems in the GPLv2 license that could let someone exploit GPL-licensed software in ways contrary to the license's intent.
These problems included tivoization, compatibility issues similar to those of the Affero General Public License—and patent deals between Microsoft and distributors of free and open-source software, which some viewed as an attempt to use patents as a weapon against the free software community. Version 3 was developed to attempt to address these concerns and was released on 29 June 2007. Version 1 of the GNU GPL, released on 25 February 1989, prevented what were the two main ways that software distributors restricted the freedoms that define free software; the first problem was that distributors may publish binary files only—executable, but not readable or modifiable by humans. To prevent this, GPLv1 stated that copying and distributing copies or any portion of the program must make the human-readable source code available under the same licensing terms; the second problem was that distributors might add restrictions, either to the license, or by combining the software with other software that had other restrictions on distribution.
The union of two sets of restrictions would apply to the combined work, thus adding unacceptable restrictions. To prevent this, GPLv1 stated that modified versions, as a whole, had to be distributed under the terms in GPLv1. Therefore, software distributed under the terms of GPLv1 could be combined with software under more permissive terms, as this would not change the terms under which the whole could be distributed. However, software distributed under GPLv1 could not be combined with software distributed under a more restrictive license, as this would conflict with the requirement that the whole be distributable under the terms of GPLv1. According to Richard Stallman, the major change in GPLv2 was the "Liberty or Death" clause, as he calls it – Section 7; the section says that licensees may distribute a GPL-covered work only if they can satisfy all of the license's obligations, despite any other legal obligations they might have. In other words, the obligations of the license may not be severed due to conflicting obligations.
This provision is intended to discourage any party from using a patent infringement claim or other litigation to impair users' freedom under the license. By 1990, it was becoming apparent that a less restrictive license would be strategically useful for the C library and for software libraries that did the job of existing proprietary ones; the version numbers diverged in 1999 when version 2.1 of the LGPL was released, which renamed it the GNU Lesser General Public License to reflect its place in the philosophy. Most "GPLv2 or any version" is stated by users of the license, to allow upgrading to GPLv3. In late 2005, the Free Software Foundation announced work on version 3 of the GPL. On 16 January 2006, the first "discussion draft" of GPLv3 was published, the public consultation began; the public consultation was planned for ni