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
Linux is a family of free and open-source software operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is packaged in a Linux distribution. Distributions include the Linux kernel and supporting system software and libraries, many of which are provided by the GNU Project. Many Linux distributions use the word "Linux" in their name, but the Free Software Foundation uses the name GNU/Linux to emphasize the importance of GNU software, causing some controversy. Popular Linux distributions include Debian and Ubuntu. Commercial distributions include SUSE Linux Enterprise Server. Desktop Linux distributions include a windowing system such as X11 or Wayland, a desktop environment such as GNOME or KDE Plasma. Distributions intended for servers may omit graphics altogether, include a solution stack such as LAMP; because Linux is redistributable, anyone may create a distribution for any purpose. Linux was developed for personal computers based on the Intel x86 architecture, but has since been ported to more platforms than any other operating system.
Linux is the leading operating system on servers and other big iron systems such as mainframe computers, the only OS used on TOP500 supercomputers. It is used by around 2.3 percent of desktop computers. The Chromebook, which runs the Linux kernel-based Chrome OS, dominates the US K–12 education market and represents nearly 20 percent of sub-$300 notebook sales in the US. Linux runs on embedded systems, i.e. devices whose operating system is built into the firmware and is tailored to the system. This includes routers, automation controls, digital video recorders, video game consoles, smartwatches. Many smartphones and tablet computers run other Linux derivatives; because of the dominance of Android on smartphones, Linux has the largest installed base of all general-purpose operating systems. Linux is one of the most prominent examples of open-source software collaboration; the source code may be used and distributed—commercially or non-commercially—by anyone under the terms of its respective licenses, such as the GNU General Public License.
The Unix operating system was conceived and implemented in 1969, at AT&T's Bell Laboratories in the United States by Ken Thompson, Dennis Ritchie, Douglas McIlroy, Joe Ossanna. First released in 1971, Unix was written in assembly language, as was common practice at the time. In a key pioneering approach in 1973, it was rewritten in the C programming language by Dennis Ritchie; the availability of a high-level language implementation of Unix made its porting to different computer platforms easier. Due to an earlier antitrust case forbidding it from entering the computer business, AT&T was required to license the operating system's source code to anyone who asked; as a result, Unix grew and became adopted by academic institutions and businesses. In 1984, AT&T divested itself of Bell Labs; the GNU Project, started in 1983 by Richard Stallman, had the goal of creating a "complete Unix-compatible software system" composed of free software. Work began in 1984. In 1985, Stallman started the Free Software Foundation and wrote the GNU General Public License in 1989.
By the early 1990s, many of the programs required in an operating system were completed, although low-level elements such as device drivers and the kernel, called GNU/Hurd, were stalled and incomplete. Linus Torvalds has stated that if the GNU kernel had been available at the time, he would not have decided to write his own. Although not released until 1992, due to legal complications, development of 386BSD, from which NetBSD, OpenBSD and FreeBSD descended, predated that of Linux. Torvalds has stated that if 386BSD had been available at the time, he would not have created Linux. MINIX was created by Andrew S. Tanenbaum, a computer science professor, released in 1987 as a minimal Unix-like operating system targeted at students and others who wanted to learn the operating system principles. Although the complete source code of MINIX was available, the licensing terms prevented it from being free software until the licensing changed in April 2000. In 1991, while attending the University of Helsinki, Torvalds became curious about operating systems.
Frustrated by the licensing of MINIX, which at the time limited it to educational use only, he began to work on his own operating system kernel, which became the Linux kernel. Torvalds began the development of the Linux kernel on MINIX and applications written for MINIX were used on Linux. Linux matured and further Linux kernel development took place on Linux systems. GNU applications replaced all MINIX components, because it was advantageous to use the available code from the GNU Project with the fledgling operating system. Torvalds initiated a switch from his original license, which prohibited commercial redistribution, to the GNU GPL. Developers worked to integrate GNU components with the Linux kernel, making a functional and free operating system. Linus Torvalds had wanted to call his invention "Freax", a portmant
StuffIt is a family of computer software utilities for archiving and compressing files. Produced for the Macintosh, versions for Microsoft Windows and Sun Solaris were created; the proprietary compression format used by the StuffIt utilities is termed StuffIt. StuffIt was developed in the summer of 1987 by Raymond Lau, a student at Stuyvesant High School in New York City, it combined the fork-combining capabilities of utilities such as MacBinary with newer compression algorithms similar to those used in ZIP. Compared to existing utilities on the Mac, notably PackIt, StuffIt offered "one step" operation and higher compression ratios. By the fall of 1987 StuffIt had replaced PackIt in the Mac world, with many software sites going so far as to convert existing PackIt archives to save more space. StuffIt soon became popular and Aladdin Systems was formed to market it, they split the product line in two, offering StuffIt Classic in shareware and StuffIt Deluxe as a commercial package. Deluxe added a variety of additional functions, including additional compression methods and integration into the Mac Finder to allow files to be compressed from a "Magic Menu" without opening StuffIt itself.
StuffIt was upgraded several times, Lau removed himself from direct development as major upgrades to the "internal machinery" were rare. Because new features and techniques appeared on the Macintosh platform, the shareware utility Compact Pro emerged as a competitor to StuffIt in the early 1990s. A major competitive upgrade followed, accompanied by the release of the freeware StuffIt Expander, to make the format more universally readable, as well as the shareware StuffIt Lite which made it easier to produce. Prior to this anyone attempting to use the format needed to buy StuffIt, making Compact Pro more attractive; this move was a success, Compact Pro subsequently fell out of use. Several other Mac compression utilities appeared and disappeared during the 1990s, but none became a real threat to StuffIt's dominance; the only ones to see any widespread use were special-purpose "disk expanders" like DiskDoubler and SuperDisk!, which served a different niche. As a side-effect, StuffIt once again saw few upgrades.
The file format changed in a number of major revisions. PC-based formats long surpassed StuffIt in terms of compression, notably newer systems like RAR and 7z; these had little impact on the Mac market, as most of these never appeared in an easy-to-use program on the Mac. With the introduction of Mac OS X, newer Mac software lost their forks and no longer needed anything except the built-in Unix utilities like gzip and tar. Numerous programs "wrapping" these utilities were distributed, since these files could be opened on any machine, they were more practical than StuffIt in an era when most data is cross-platform. With the release of OS X Public Beta, Aladdin Systems released StuffIt 6.0 which runs under OS X, with Expander no longer relying on the StuffIt Engine™. Although it was late to market, Aladdin Systems introduced the new StuffIt X format in September 2002 with StuffIt Deluxe 7.0 for Macintosh. It was designed to be extendable, support more compression methods, support long file names, support Unix and Windows file attributes.
StuffIt X improves over the original StuffIt format and its descendants by adding multiple compression algorithms such as PPM, BWT to LZW-type compression. It added a "block mode" option and several encryption options. In January 2005, JPEG compression was added as a StuffIt X compression option. From the mid-1990s until the 2005 acquisition by Smith Micro Software, coinciding with the release of Mac OS X v10.4 "Tiger," StuffIt Expander came bundled with the Macintosh operating system. Although Mac files did not use filename extensions, one of StuffIt's primary uses was to allow Mac files to be stored on non-Mac systems where extensions were required. So, StuffIt-compressed files save the resource forks of the Macintosh files inside them, have the extension.sit. Newer Stuffit X-compressed files carry the file extension.sitx. Encrypted StuffIt archives created with the now-discontinued Private File utility will have.pf extensions. StuffIt-compressed ShrinkWrap disk images will carry.img or.image extensions.
However, a Classic Mac OS version of StuffIt is needed to mount the images or convert them to a newer format readable in macOS. Smith Micro Software offers free downloads of StuffIt Expander for Mac and Windows, which expands files compressed using the StuffIt and StuffIt X format, as well as many other compressed, encoded and segmented formats; the shareware application DropStuff permits the compressing of files into the StuffIt X format. The StuffIt and StuffIt X formats remain, unlike some other file compression formats and Smith Micro Software charge license fees for its use in other programs. Given this, few alternative programs support the format. There was an "self-expanding" variant of StuffIt files with a.sea extension that runs as an executable. A utility called. Early in 2005, a new JPEG compression system was released that obtained compression in the order of 25% without any further loss of image quality and with the ability to rebuild the original file, not just the original image.
(ZIP-like programs achieve JPEG compression rates in the order of 1 to 3%. Programs that optimise JPEGs without regard for the original file, only the original image
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
Zipeg is an open source free software that extracts files from compressed archives like ZIP, RAR, 7z and others, some of which are used types. Zipeg works under Windows, it is best known for its file preview ability. It is incapable of compressing files. Zipeg is built on top of the 7-Zip backend, its UI is open source. Zipeg automatically detects filenames in national alphabets and translates them to Unicode. Zipeg reads Exif thumbnails from JPEG digital photographs and uses them for "tool tip" style preview and item icons. Zip Data compression Zipeg review from c|net Zipeg review by Macworld Zipeg main site http://www.zipeg.com/ Zipeg source code https://code.google.com/archive/p/zipeg/#
MacOS is a series of graphical operating systems developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac family of computers. Within the market of desktop and home computers, by web usage, it is the second most used desktop OS, after Microsoft Windows.macOS is the second major series of Macintosh operating systems. The first is colloquially called the "classic" Mac OS, introduced in 1984, the final release of, Mac OS 9 in 1999; the first desktop version, Mac OS X 10.0, was released in March 2001, with its first update, 10.1, arriving that year. After this, Apple began naming its releases after big cats, which lasted until OS X 10.8 Mountain Lion. Since OS X 10.9 Mavericks, releases have been named after locations in California. Apple shortened the name to "OS X" in 2012 and changed it to "macOS" in 2016, adopting the nomenclature that they were using for their other operating systems, iOS, watchOS, tvOS; the latest version is macOS Mojave, publicly released in September 2018.
Between 1999 and 2009, Apple sold. The initial version, Mac OS X Server 1.0, was released in 1999 with a user interface similar to Mac OS 8.5. After this, new versions were introduced concurrently with the desktop version of Mac OS X. Beginning with Mac OS X 10.7 Lion, the server functions were made available as a separate package on the Mac App Store.macOS is based on technologies developed between 1985 and 1997 at NeXT, a company that Apple co-founder Steve Jobs created after leaving the company. The "X" in Mac OS X and OS X is pronounced as such; the X was a prominent part of the operating system's brand identity and marketing in its early years, but receded in prominence since the release of Snow Leopard in 2009. UNIX 03 certification was achieved for the Intel version of Mac OS X 10.5 Leopard and all releases from Mac OS X 10.6 Snow Leopard up to the current version have UNIX 03 certification. MacOS shares its Unix-based core, named Darwin, many of its frameworks with iOS, tvOS and watchOS.
A modified version of Mac OS X 10.4 Tiger was used for the first-generation Apple TV. Releases of Mac OS X from 1999 to 2005 ran on the PowerPC-based Macs of that period. After Apple announced that they were switching to Intel CPUs from 2006 onwards, versions were released for 32-bit and 64-bit Intel-based Macs. Versions from Mac OS X 10.7 Lion run on 64-bit Intel CPUs, in contrast to the ARM architecture used on iOS and watchOS devices, do not support PowerPC applications. The heritage of what would become macOS had originated at NeXT, a company founded by Steve Jobs following his departure from Apple in 1985. There, the Unix-like NeXTSTEP operating system was developed, launched in 1989; the kernel of NeXTSTEP is based upon the Mach kernel, developed at Carnegie Mellon University, with additional kernel layers and low-level user space code derived from parts of BSD. Its graphical user interface was built on top of an object-oriented GUI toolkit using the Objective-C programming language. Throughout the early 1990s, Apple had tried to create a "next-generation" OS to succeed its classic Mac OS through the Taligent and Gershwin projects, but all of them were abandoned.
This led Apple to purchase NeXT in 1996, allowing NeXTSTEP called OPENSTEP, to serve as the basis for Apple's next generation operating system. This purchase led to Steve Jobs returning to Apple as an interim, the permanent CEO, shepherding the transformation of the programmer-friendly OPENSTEP into a system that would be adopted by Apple's primary market of home users and creative professionals; the project was first code named "Rhapsody" and officially named Mac OS X. Mac OS X was presented as the tenth major version of Apple's operating system for Macintosh computers. Previous Macintosh operating systems were named using Arabic numerals, as with Mac OS 8 and Mac OS 9; the letter "X" in Mac OS X's name refers to a Roman numeral. It is therefore pronounced "ten" in this context. However, it is commonly pronounced like the letter "X"; the first version of Mac OS X, Mac OS X Server 1.0, was a transitional product, featuring an interface resembling the classic Mac OS, though it was not compatible with software designed for the older system.
Consumer releases of Mac OS X included more backward compatibility. Mac OS applications could be rewritten to run natively via the Carbon API; the consumer version of Mac OS X was launched in 2001 with Mac OS X 10.0. Reviews were variable, with extensive praise for its sophisticated, glossy Aqua interface but criticizing it for sluggish performance. With Apple's popularity at a low, the makers of several classic Mac applications such as FrameMaker and PageMaker declined to develop new versions of their software for Mac OS X. Ars Technica columnist John Siracusa, who reviewed every major OS X release up to 10.10, described the early releases in retrospect as'dog-slow, feature poor' and Aqua as'unbearably slow and a huge resource hog'. Apple developed several new releases of Mac OS X. Siracusa's review of version 10.3, noted "It's strange to have gone from years of uncertainty and vaporware to a steady annual supply of major new operating system releases." Version 10.4, Tiger shocked executives at Microsoft by offering a number of features, such as fast file s
DOS is a family of disk operating systems, hence the name. DOS consists of MS-DOS and a rebranded version under the name IBM PC DOS, both of which were introduced in 1981. Other compatible systems from other manufacturers include DR-DOS, ROM-DOS, PTS-DOS, FreeDOS. MS-DOS dominated the x86-based IBM PC compatible market between 1981 and 1995. Dozens of other operating systems use the acronym "DOS", including the mainframe DOS/360 from 1966. Others are Apple DOS, Apple ProDOS, Atari DOS, Commodore DOS, TRSDOS, AmigaDOS. Fictional operating systems have used this acronym as well, such as GLaDOS from the video game Portal. IBM PC DOS and its predecessor, 86-DOS, resembled Digital Research's CP/M—the dominant disk operating system for 8-bit Intel 8080 and Zilog Z80 microcomputers—but instead ran on Intel 8086 16-bit processors; when IBM introduced the IBM PC, built with the Intel 8088 microprocessor, they needed an operating system. Seeking an 8088-compatible build of CP/M, IBM approached Microsoft CEO Bill Gates.
IBM was sent to Digital Research, a meeting was set up. However, the initial negotiations for the use of CP/M broke down. Digital Research founder Gary Kildall refused, IBM withdrew. IBM again approached Bill Gates. Gates in turn approached Seattle Computer Products. There, programmer Tim Paterson had developed a variant of CP/M-80, intended as an internal product for testing SCP's new 16-bit Intel 8086 CPU card for the S-100 bus; the system was named QDOS, before being made commercially available as 86-DOS. Microsoft purchased 86-DOS for $50,000; this became Microsoft Disk Operating System, MS-DOS, introduced in 1981. Within a year Microsoft licensed MS-DOS to over 70 other companies, which supplied the operating system for their own hardware, sometimes under their own names. Microsoft required the use of the MS-DOS name, with the exception of the IBM variant. IBM continued to develop their version, PC DOS, for the IBM PC. Digital Research became aware that an operating system similar to CP/M was being sold by IBM, threatened legal action.
IBM responded by offering an agreement: they would give PC consumers a choice of PC DOS or CP/M-86, Kildall's 8086 version. Side-by-side, CP/M cost $200 more than PC DOS, sales were low. CP/M faded, with MS-DOS and PC DOS becoming the marketed operating system for PCs and PC compatibles. Microsoft sold MS-DOS only to original equipment manufacturers. One major reason for this was. DOS was structured such that there was a separation between the system specific device driver code and the DOS kernel. Microsoft provided an OEM Adaptation Kit which allowed OEMs to customize the device driver code to their particular system. By the early 1990s, most PCs adhered to IBM PC standards so Microsoft began selling MS-DOS in retail with MS-DOS 5.0. In the mid-1980s Microsoft developed a multitasking version of DOS; this version of DOS is referred to as "European MS-DOS 4" because it was developed for ICL and licensed to several European companies. This version of DOS supports preemptive multitasking, shared memory, device helper services and New Executable format executables.
None of these features were used in versions of DOS, but they were used to form the basis of the OS/2 1.0 kernel. This version of DOS is distinct from the released PC DOS 4.0, developed by IBM and based upon DOS 3.3. Digital Research attempted to regain the market lost from CP/M-86 with Concurrent DOS, FlexOS and DOS Plus with Multiuser DOS and DR DOS. Digital Research was bought by Novell, DR DOS became Novell DOS 7. Gordon Letwin wrote in 1995 that "DOS was, when we first wrote it, a one-time throw-away product intended to keep IBM happy so that they'd buy our languages". Microsoft expected; the company planned to over time improve MS-DOS so it would be indistinguishable from single-user Xenix, or XEDOS, which would run on the Motorola 68000, Zilog Z-8000, LSI-11. IBM, did not want to replace DOS. After AT&T began selling Unix, Microsoft and IBM began developing OS/2 as an alternative; the two companies had a series of disagreements over two successor operating systems to DOS, OS/2 and Windows.
They split development of their DOS systems as a result. The last retail version of MS-DOS was MS-DOS 6.22. The last retail version of PC DOS was PC DOS 2000, though IBM did develop PC DOS 7.10 for OEMs and internal use. The FreeDOS project began on 26 June 1994, when Microsoft announced it would no longer sell or support MS-DOS. Jim Hall posted a manifesto proposing the development of an open-source replacement. Within a few weeks, other programmers including Pat Villani and Tim Norman joined the project. A kernel, the COMMAND. COM command line interpreter, core utilities were created by pooling code they had wri