This is my school project.Also my homework.Hope you enjoy it!
Computeristic World Welcome to the
A computer is a programmable machine which
can receive physical input through an accessory, the two most common being a keyboard and mouse. The it can convert this into a basic computer thing, such as a letter being entered, or clicking something on the screen. When something basic like typing is done, the letter or number on the screen is the converted output. The typing of these letters on the screen had to go through this conversion process. There are other ways in which put letters on a screen, such as copying and pasting, or downloading a ready typed alphanumerically processed file.
Starting a computer
The starting of a computer is simple when you don’t think about it carefully.
All you need to do is just press a button then your computer begins the start up process. When you press the button, the computer starts to consume electricity, the power source for a computer. The computer then finds what people can call an OS or boot media. The two capital letters O and S put together make an abbreviation for two words put together. Operating System. The boot media or the OS is the software the computer use. Three of the most popular and well known boot medias and OS’s are Windows, Linux, Mac OS and Mac OS X.
Mac OS X
An OS is the software that handles the
What is an OS?
computer,for example,it lets you execute programs,view media and other things similar to that.It also performs the processes which the computer and the OS need to run.It needs to handle other things as well like the hard drive,which can be known as a HDD,and the memory,the processor,graphics and video cards,otherwise the OS would not work at all.
OS-Boot Media use
The 4 computer OS’s-Boot Medias in the last slide are used a different
amount by everyone around the world.From March 2010,these are usage of the boot medias-OS’s.Mac OS is not on here because it is really the same kind of thing as Mac OS X.
Microsoft software use
Microsoft,a company which is 35 years old,established 1975 April 4th
by Bill Gates,has constructed a family of computer software called Windows.Microsoft Windows has top usage of all computer software. All their software will be listed in other slides.
Windows 1.0 was the first OS in the Windows family, and the second manufactured OS by
Microsoft Windows 1.0
Microsoft. It isn’t really an OS because it wasn’t the OS that handled the computer. The computer was handled by a simple to run application called MS-DOS.MS-DOS stands for Microsoft Disk Operating System. When it was released, it was released as1.01.To let it run on a computer, you need a floppy disk with the Windows 1.0 boot data on it. This version of Windows was made in 1985.If you went back to 1985 with Windows 1.0,HDD space and memory space would be scarce compared to now. The hard drive below is 40gb.GB is short for gigabyte.1gb is 1024mb.MB is short for a megabyte.1mb is 1024kb.A KB is short for a kilobyte.1kb is 1024b.B is short for a byte. There are two others which are higher than a GB. There is a TB.TB is short a terabyte.1tb is 1024gb.Then you have a PB.A PB is a petabyte.1pb is 1024tb.
T h e vi e o to th e ri h t d g w h e re th e a rro w i s p o i ti g w i l p l y w h e n n n l a yo u cl ck i . I w i l sh o w i t t l yo u a b o u t W i d o w s 1 . 0 . n
Windows 2.0 was a 16-bit GUI based OE that surpassed Windows 2.0.A GUI is short for an
graphical user interface,and an OE is an operating enviroment.This version of Microsoft Windows was the 3rd OS made by Microsoft and the 2nd OS in the Microsoft Windows family of operating systems.This version of the Windows OS was superseded by Windows 3.0 which was released in May 1990.Windows 2.0 was supplemented by Windows/286 and Windows/386 in 1988.The supplements of Windows 2.0 along with Windows 2.0 itself were all superseded by Windows 3.0 as well.
T h e re w i lb e a vi e o b e l w a b o u t l d o W i d o w s 2 .0 . n
Windows 3.0 succeeded Windows 2.1x and included a significantly revamped user interface as
well as technical improvements to make better use of the memory management capabilities of the 80286 and 80386 processors. Text-mode programs written for MS-DOS could be run within a window (a feature previously available in a more limited form with Windows/386 2.1), making the system usable as a crude multitask base for legacy programs. However, this was of limited use for the home market, where most games and entertainment programs continued to require raw DOS access. The MS-DOS Executive file manager/program launcher was replaced with the icon-based Program Manager and the listbased File Manager, thereby simplifying the launching of applications. The MS-DOS Executive is also included as an alternative to these. The Control Panel, previously available as a standard-looking applet, was re-modeled after the one in Mac OS. It centralized system settings, including limited control over the color scheme of the interface. A number of simple applications were included, such as the text editor Notepad and the word processor Write (both inherited from earlier versions of Windows), a macro recorder (new; later dropped), the paint program Paintbrush (inherited but substantially improved), and a calculator (also inherited). Also, the earlier Reversi game was complemented with the card game solitare. The Windows icons and graphics were redesigned to take advantage of VGA‘s 16-color mode. Earlier versions only supported eight colors though could run on monochrome video adapters. Windows 3.0 also allowed the user to use a 256 color video adapter, whereas previous versions only supported 16 colors.The video below will show you the running of Windows 3.0.
Windows 3.1x is a series of 16-bit operating environments produced by Microsoft for use on personal computers.
The series began with Windows 3.1, which was first sold during March 1992 as a successor to Windows 3.0. Further editions were released between 1992 and 1994 until the series was superseded by Windows 95. Windows 3.1 (originally codenamed Janus, of which two betas were published), released in April 1992, includes a TrueType font system (and a set of highly legible fonts already installed), which effectively made Windows a serious desktop publishing platform for the first time. Similar functionality was available for Windows 3.0 through the Adobe Type Manager (ATM) font system from Adobe. Windows 3.1 was designed to have backward compatibility with older Windows platforms. As with Windows 3.0, version 3.1 had File Manager and Program Manager, but unlike all previous versions, Windows 3.1 and later support 32-bit disk access, cannot run in real mode, and included Minesweeper instead of Reversi (though Reversi was included in some copies). Windows 3.1 Multimedia PC Version (Beta only, released Nov 1992 — codenamed Bombay) Included a media viewer, and the ability to play video files. It was targeted to the the new multi-media PC and included sound and video integration with CD-ROM support.
Fascinating Fact:These Windows OSs were the main few in the 80s and 90s. A video of this OS will be below.
Windows 95 is a consumer-oriented graphical user interface-based operating environment. It was
released on August 24, 1995 by Microsoft , and was a significant progression from the company's previous Windows products. During development it was referred to as Windows 4.0 or by the internal codename Chicago. Windows 95 was intended to integrate Microsoft's formerly separate MSDOS and Windows products, however it is still considered an operating environment that sits over the DOS operating system. It features significant improvements over its predecessor, Windows 3.1, most notably in the graphical user interface (GUI) and in its simplified "plug-nplay" features. There were also major changes made at lower levels of the operating system. In the marketplace, Windows 95 was a major success, and within a year or two of its release had become the most successful operating system ever produced. It also had the effect of driving other major players in the DOS-compatible operating system market out of business, something which would later be used in court against Microsoft. Some three years after introduction, Windows 95 was succeeded by Windows 98.
V i e o n e a r a rro w . d
Windows 98 (codenamed Memphis) is a graphical operating system by Microsoft. It was
released to manufacturing on May 15, 1998 and to retail on June 25, 1998. Windows 98 is the successor to Windows 95. Like its predecessor, it is a hybrid 16-bit/32-bitmonolithic product with an MS-DOS based boot loader. Windows 98 was succeeded by Windows Me on September 14, 2000. Microsoft support for Windows 98 ended on July 11, 2006. Windows 98 was the first operating system to use the Windows Driver Model (WDM). This fact was not well published when Windows 98 was released and most hardware producers continued to develop drivers for the older driver standard, VxD. The WDM standard spread years after its release, mostly through Windows 2000 and Windows XP, because these systems are not compatible with the older VxD standard. Today, even if hardware producers are not developing drivers optimized for Windows 98, the drivers written to WDM standards are compatible with Windows 98-based systems.
Lo o k o n to p m oef fo r a vi io d o f W en d o w s 98!! H o p e yo u e n j y o
Windows 2000 is a line of operating systems produced by Microsoft for use on business
desktops, notebook computers, and servers. Released on 17 February 2000, it was the successor to Windows NT 4.0, and is the final release of Microsoft Windows to display the "Windows NT" designation. It was succeeded by Windows XP for desktop systems in October 2001 and Windows Server 2003 for servers in April 2003. Four editions of Windows 2000 were
released: Professional, Server, Advanced Server, and Datacenter Server. Additionally, Microsoft sold Windows 2000 Advanced Server Limited Edition and Windows 2000 Datacenter Server Limited Edition, which were released in 2001 and run on 64-bit Intel Itanium microprocessors. While each edition of Windows 2000 was targeted to a different market, they share a core set of features, including many system utilities such as the Microsoft Management Console and standard system administration applications. Support for people with disabilities has been improved over Windows NT 4.0 with a number of new assistive technologies, and Microsoft increased support for different languages and locale information. All versions of the operating system support the Windows NT file system, NTFS 3.0, the Encrypting File System, as well as basic and dynamic disk storage. The Windows 2000 Server family has additional features, including the ability to provide Active Directory services (a hierarchical framework of resources), Distributed File System (a file system that supports sharing of files) and fault-redundant storage volumes. Windows 2000 can be installed through either a manual or unattended installation. Unattended installations rely on the use of answer files to fill in installation information, and can be performed through a bootable CD using Microsoft Systems Management Server, by the System Preparation Tool. Microsoft marketed Windows 2000 as the most secure Windows version ever,[ but it became the target of a number of high-profile virus attacks such as Code Red and Nimda. Over ten years after its release, it continues to receive patches for security vulnerabilities nearly every month and will continue to do so until 13 July 2010.
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Windows ME is the Millennium Edition of the Microsoft Windows operating system. Windows Me is based on Windows 98. Windows Me was based on MS-DOS (as were Windows 98 and Windows 95), and is meant for people using computers in their homes. Windows 2000 and Windows Me are similar in looks, but Windows Me has features that families find useful, while Windows 2000 was meant for businesses. It was released near the year 2000 because it was the Third Millennium, calling it Windows Millennium Edition. Windows Millennium Edition, or Windows Me (pronounced either as a word, /ˈmiː/ me, or as an abbreviation, /ˌɛm ˈiː/em-ee, is a graphical operating system released on September 14, 2000 by Microsoft. Support for Windows Me ended on July 11, 2006  . Windows Me was the successor to Windows 98 and, just like Windows 98, was targeted specifically at home PC users  . It included Internet Explorer 5.5, Windows Media Player 7, and the new Windows Movie Maker software, which provided basic video editing and was designed to be easy for home users. Microsoft also updated the graphical user interface and the shell features and Windows Explorer in Windows Me with some of those first introduced in Windows 2000, which had been released as a business oriented operating system seven months earlier. Windows Me could be upgraded to Internet Explorer 6 SP1, but not to SP2 (SV1) or Internet Explorer 7, and Windows Media Player 9 Series. Microsoft .NET Framework up to and including version 2.0 is supported, however versions 2.0 SP1, 3.x, and greater are not. Office XP was the last version of Microsoft Office to be compatible with Windows 9x. Windows Me is a continuation of the Windows 9x model, but with access to real mode MS-DOS restricted in order to speed up system boot time  . This was one of the most publicized changes in Windows Me, because applications that needed real mode DOS to run, such as older disk utilities, did not run under Windows Me. Compared with other releases of Windows, Windows Me had a short shelf-life of just over a year; it was soon replaced by the Windows NT-based Windows XP, which was launched on October 25, 2001.
V i A b o ve . d
Windows XP is an operating system produced by Microsoft for use on personal computers,
including home and business desktops, laptops, and media centers. It was released in 2001. The name "XP" is short for "eXPerience." Windows XP is the successor to both Windows 2000 Professional and Windows Me, and is the first consumer-oriented operating system produced by Microsoft to be built on the Windows NT kernel and architecture. Windows XP was first released on October 25, 2001, and over 400 million copies were in use in January 2006, according to an estimate in that month by an IDC analyst. It was succeeded by Windows Vista, which was released to volume license customers on November 8, 2006, and worldwide to the general public on January 30, 2007. Direct OEM and retail sales of Windows XP ceased on June 30, 2008. Microsoft continued to sell XP through their System Builders (smaller OEMs who sell assembled computers) program until January 31, 2009. XP may continue to be available as these sources run through their inventory or by purchasing Windows Vista Ultimate or Business and then downgrading to Windows XP. The most common editions of the operating system are Windows XP Home Edition, which is targeted at home users, and Windows XP Professional, which offers additional features such as support for Windows Server domains and two physical processors, and is targeted at power users, business and enterprise clients. Windows XP Media Center Edition has additional multimedia features enhancing the ability to record and watch TV shows, view DVD movies, and listen to music. Windows XP Tablet PC Edition is designed to run stylus applications built using the Tablet PC platform.
V i e o A b o ve . d
Windows Vista is a line of operating systems developed by Microsoft for use on personal
computers, including home and business desktops, laptops, tablet PCs, and media center PCs. Prior to its announcement on July 22, 2005, Windows Vista was known by its codename "Longhorn." Development was completed on November 8, 2006; over the following three months it was released in stages to computer hardware and software manufacturers, business customers, and retail channels. On January 30, 2007, it was released worldwide, and was made available for purchase and download from Microsoft's website. The release of Windows Vista came more than five years after the introduction of its predecessor, Windows XP, the longest time span between successive releases of Microsoft Windows desktop operating systems. It was succeeded by Windows 7 which was released to manufacturing on July 22, 2009, and for the general public on October 22, 2009. Windows Vista contains many changes and new features, including an updated graphical user interface and visual style dubbed Aero, a redesigned search function, multimedia tools including Windows DVD Maker, and redesigned networking, audio, print, and display subsystems. Vista aims to increase the level of communication between machines on a home network, using peer-to-peer technology to simplify sharing files and media between computers and devices. Windows Vista includes version 3.0 of the .NET Framework, allowing software developers to write applications without traditional Windows APIs.
V i a b o ve m e ! d Enj y i! o t
Windows 7 is a version of Microsoft Windows, a series of operating systems produced by Microsoft for use
on personal computers, including home and business desktops, laptops, net books, tablet PCs, and media center PCs. Windows 7 was released to manufacturing on July 22, 2009, and reached general retail availability on October 22, 2009, less than three years after the release of its predecessor, Windows Vista. Windows 7's server counterpart, Windows Server 2008 R2, was released at the same time. Windows 7 will be succeeded by Windows 8, which has no release date as of yet. Unlike its predecessor, which introduced a large number of new features, Windows 7 was intended to be a more focused, incremental upgrade to the Windows line, with the goal of being compatible with applications and hardware with which Windows Vista is already compatible. Presentations given by Microsoft in 2008 focused on multi-touch support, a redesigned Windows Shell with a new taskbar, referred to as the Superbar, a home networking system called HomeGroup, and performance improvements. Some applications that have been included with prior releases of Microsoft Windows, including Windows Calendar, Windows Mail, Windows Movie Maker, and Windows Photo Gallery, are not included in Windows 7; most are instead offered separately at no charge as part of the Windows Live Essentials suite.
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Mac OS X
Mac OS X was founded by Apple Incorporations
for use on computers as a main rival for Microsoft’s own OS,Windows.
Mac OS X version 10.0, code named “Cheetah”, is the first major release of Mac OS X, Apple’s
Mac OS X 10.0 - Cheetah
desktop and server operating system. Mac OS X v10.0 was released on March 24, 2001 for a price of US$129. It superseded the Mac OS X Public Beta and preceded Mac OS X v10.1. Mac OS X v10.0 was a radical departure from the previous “classic” Macintosh operating system and was Apple’s long awaited answer to the call for a next generation Macintosh operating system. It introduced a brand new code base completely separate from Mac OS 9's, as well as all previous Apple operating systems. Mac OS X introduced the new Darwin Unix-like core and a totally new system of memory management. It proved to be a rocky start to the Mac OS X line, plagued with missing features and performance issues, although it was praised for being a good start to an operating system still in its infancy, in terms of completeness and overall operating system stability.
Mac OS X version 10.1, code named “Puma”, is the second major release of Mac OS X, Apple’s
Mac OS X 10.1 - Puma
desktop and server operating system. It superseded Mac OS X v10.0 and preceded Mac OS X v10.2. Version 10.1 was released on September 25, 2001 as a 'free update' to version 10.0. Starting with version 10.1.2, Apple made Mac OS X the default operating system on new Macs. The operating system was handed out for no charge by Apple employees after Steve Jobs' keynote speech at the Seyboldpublishing conference in San Francisco.[citationneeded ] It was subsequently distributed to Macintosh users on October 25, 2001 atApple Stores and other retail stores that carried Apple products. The operating system was better received than Mac OS X version 10.0, although critics claimed that the operating system was still lacking features and was plagued with bugs.
Mac OS X version 10.2 “Jaguar” is the third major release of Mac OS X, Apple’s desktop and
Mac OS X 10.2 - Jaguar
server operating system. It superseded Mac OS X v10.1 code name Puma and preceded Mac OS X v10.3 “Panther”. The operating system was initially available on 23 August 2002 either for single-computer installations, and in a "family pack", which allows five installations on separate computers in one household. The operating system was generally well-received by Macintosh users as a large step forward in the areas of stability, general speed enhancements, and the lineup of both graphical and command line applications available; however, many critics still claimed that significant user interface speed issues existed and that the operating system was still immature and awkward to use. Jaguar was the first Mac OS X release to publicly use its code name in marketing and advertisements, a practice that has continued in subsequent releases of the operating system.
Mac OS X version 10.3 “Panther” is the fourth major release of Mac OS X, Apple’s desktop and server operating system. It followed Mac OS X v10.2 “Jaguar” and preceded Mac OS X v10.4 “Tiger”. Apple released Panther on October 24, 2003. Since a New World ROM is required for Mac OS X v10.3 (“Panther”), certain older computers (such as beige Power Mac G3s and “Wall Street” PowerBook G3s) are unable to run Panther by default. Third-party software (such as XPostFacto) can, however, override checks made during the install process; otherwise, installation or upgrades from Jaguar will fail on these older machines. Panther still supported the Classic environment fully for running older Mac OS 9 applications. Finder – Updated with a brushed-metal interface, a new real-time search engine, customizable Sidebar, secure deletion, File labels and Zip support built in. Finder logo changed.Fast User Switching – Allows a user to remain logged in while another user logs in. Exposé – Helps the user manage windows by showing them all as thumbnails.TextEdit – TextEdit now is also compatible with Microsoft Word (.doc) documents. Xcode developer tools – Faster compile times with gcc 3.3.Preview – Increased speed with PDF rendering. QuickTime – Now supports the Pixlet high definition video codec. Font Book – New application that functions as font manager File Vault – On the fly encryption and decryption of a user’s home folder iChat AV – The new version of iChat. Now with built-in Audio- and video-conferencing. X11 – X11 is built into Panther Safari - New browser made to replace Internet Explorer for Mac OS X, developed when the contract between Apple and Microsoft ended. Internet Explorer for Mac was still available but not supported by Microsoft or Apple. This was included in an update on 10.2 but was used as the default browser in Panther.
Mac OS X 10.3 - Panther
Mac OS X Tiger (version 10.4) is the fifth major release of Mac OS X, Apple’s desktop and server
Mac OS X 10.4 - Tiger
operating system for Macintosh computers. Tiger was released to the public on 29 April 2005 for US$129.95 as the successor to Mac OS X Panther (version 10.3), which had been released 18 months earlier. Tiger was succeeded by Mac OS X Leopard (version 10.5) on 26 October 2007, after 30 months, making Tiger the longest running version of Mac OS X. Some of the new features include a fast searching system called Spotlight, a new version of the Safari web browser, Dashboard, a new ‘Unified’ theme, and improved support for 64-bit addressing on Power Mac G5s. Tiger was included with all new Macintosh computers, and was also available as an upgrade for existing Mac OS X users, or users of supported pre-Mac OS X systems. The server edition, Mac OS X Server 10.4, was also available for some Macintosh product lines. Tiger is also the first version of any released Apple operating system to work on Apple-Intel architecture machines (Apple machines using x86 processors). The Apple TV, as released in March 2007, ships with a customized version of Mac OS X v10.4 branded "Apple TV OS" that replaces the usual graphical user interface with an updated version of Front Row.
Mac OS X Leopard (version 10.5) is the sixth major release of Mac OS X, Apple’s desktop and
Mac OS X 10.5 - Leopard
server operating system for Macintosh computers. Leopard was released on 26 October 2007 as the successor of Mac OS X Tiger (version 10.4), and is available in two variants: a desktop version suitable for personal computers, and a server version, Mac OS X Server. Steve Jobs stated at Macworld 2008 that over 20% of Macs use Leopard as their operating system. Leopard was superseded by Mac OS X Snow Leopard (version 10.6). Leopard is the final version of Mac OS X to support the PowerPC architecture as Snow Leopard solely functions on Intel based Macs. With the release of Snow Leopard, Leopard will only be maintained with security updates until the next shipping version of Mac OS X. According to Apple, Leopard contains over 300 changes and enhancements over its predecessor, Mac OS X Tiger,covering core operating system components as well as included applications and developer tools. Leopard introduces a significantly revised desktop, with a redesigned Dock, Stacks, a semitransparent menu bar, and an updated Finder that incorporates the Cover Flow visual navigation interface first seen in iTunes. Other notable features include support for writing 64-bit graphical user interface applications, an automated backup utility called Time Machine, support for Spotlight searches across multiple machines, and the inclusion of Front Row and Photo Booth, which were previously included with only some Mac models. Apple missed Leopard's release time frame as originally announced by Apple’s CEO Steve Jobs. When first discussed in June 2005, Jobs had stated that Apple intended to release Leopard at the end of 2006 or early 2007. A year later, this was amended to Spring 2007; however on 12 April 2007, Apple issued a statement that its release would be delayed until October 2007 because of the development of the iPhone.
Mac OS X Snow Leopard (version 10.6) is the seventh and current major release of Mac OS X,
Apple's desktop and server certified Unix operating system. Snow Leopard was announced by Steve Jobs on June 8, 2008 at WWDC 2008 but was not publicly unveiled until the following year on June 8, 2009 at the same conference. On August 28, 2009, it was released worldwide, and was made available for purchase from Apple's website and its retail stores at the price of $29 for a single-user license. As a result of the low price, initial sales of Snow Leopard were significantly higher than that of its predecessors. The release of Snow Leopard came nearly two years after the introduction of Mac OS X v10.5 "Leopard," the second longest time span between successive Mac OS X releases. Unlike previous versions of Mac OS X, the goal with Snow Leopard was to improve performance, efficiency and reduce its overall memory footprint instead of to add new end-user features. Much of the software in Mac OS X was extensively rewritten for this release in order to fully take advantage of modern Macintosh hardware. New programming languages, such as OpenCL, were created, allowing software developers to use graphics cards in their applications. This is also the first Mac OS release since the introduction of System 7.1.2 that does not support the PowerPC architecture, as Apple now intends to focus on its current line of Intel-based products.
SUSE Linux (pronounced /ˈsuːsə/, German: [ˈzuːzə]) is a computer operating system. It is built on
top of the Linux kernel and is distributed with system and application software from various projects. SUSE Linux is of German origin and mainly developed in Europe. The first version of this distribution appeared in early 1994, making SUSE the oldest existing commercial distribution. It is known for its YaST configuration tool. The developer rights are owned by Novell, Inc. since 2003, when the company bought SUSE. Novell, one of the founding members of the Open Invention Network, decided to make the community an important part of their development process by opening widely the distribution development to outside contributors in 2005, creating the openSUSE Project. Novell employed over 500 developers working on SUSE in 2004.
Red Hat Linux, assembled by the company Red Hat, was a popular Linux based operating system
Red Hat Linux
until its discontinuation in 2004. Red Hat Linux 1.0 was released on November 3, 1994. It was originally called "Red Hat Commercial Linux" It was the first Linux distribution to use the RPM Package Manager as its packaging format, and over time has served as the starting point for several other distributions, such as Mandriva Linux and Yellow Dog Linux. Since 2003, Red Hat has discontinued the Red Hat Linux line in favor of Red Hat Enterprise Linux (RHEL) for enterprise environments. Fedora, developed by the community-supported Fedora Project and sponsored by Red Hat, is the free version best suited for home use. Red Hat Linux 9, the final release, hit its official end-of-life on 2004-04-30, although updates were published for it through 2006 by the Fedora Legacy project until that shut down in early 2007.
Debian (pronounced /ˈdɛbiən/) is a computer operating system composed of software packages
released as free and open source software especially under the GNU General Public License and other free software licenses. The primary form, Debian GNU/Linux, which uses the Linux kernel and GNU OS tools, is a popular and influential GNU/Linux distribution. It is distributed with access to repositories containing thousands of software packages ready for installation and use. Debian is known for relatively strict adherence to the Unix and free software philosophies as well as using collaborative software development and testing processes. Debian can be used as a desktop as well as server operating system. It focuses on stability and security and is used as a base for many other distributions.
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, and Joe Ossanna. Unix derived its name as a joke and reference to an experimental operating system that was slow and ineffective called MULTICS. It was first released in 1971 and was initially entirely written in assembly language, a common practice at the time. Later, in a key pioneering approach in 1973, Unix was re-written in the programming language C by Dennis Ritchie, (with exceptions to the kernel and I/O). The availability of an operating system written in a high-level language allowed easier portability to different computer platforms. With a legal glitch forcing AT&T to license the operating system's source code, Unix quickly grew and became widely adopted by academic institutions and businesses.