A live CD (also live DVD, live disc, or live operating system) is a complete

bootable In computing, booting is the process of starting a computer as initiated via hardware such as a button or by a software command. After it is switched on, a computer's central processing unit (CPU) has no software in its main memory, so some ...

computer installation including

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

which runs directly from a

CD-ROM A CD-ROM (, compact disc read-only memory) is a type of read-only memory consisting of a pre-pressed optical compact disc that contains data. Computers can read—but not write or erase—CD-ROMs. Some CDs, called enhanced CDs, hold both comput ...

or similar storage device into a computer's memory, rather than loading from a hard disk drive. A live CD allows users to run an

for any purpose without installing it or making any changes to the computer's configuration. Live CDs can run on a computer without secondary storage, such as a hard disk drive, or with a corrupted hard disk drive or file system, allowing

data recovery In computing, data recovery is a process of retrieving deleted, inaccessible, lost, corrupted, damaged, or formatted data from secondary storage, removable media or files, when the data stored in them cannot be accessed in a usual way. The dat ...

. As CD and DVD drives have been steadily phased-out, live CDs have become less popular, being replaced by

live USB A live USB is a portable USB-attached external data storage device containing a full operating system that can be booted from. The term is reminiscent of USB flash drives but may encompass an external hard disk drive or solid-state drive, th ...

s, which are equivalent systems written onto

USB flash drive A USB flash drive (also called a thumb drive) is a data storage device that includes flash memory with an integrated USB interface. It is typically removable, rewritable and much smaller than an optical disc. Most weigh less than . Since firs ...

s, which have the added benefit of having writeable storage. The functionality of a live CD is also available with an

external hard disk drive A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magneti ...

connected by USB. Many live CDs offer the option of persistence by writing files to a hard drive or USB flash drive. Many Linux distributions make

ISO image An optical disc image (or ISO image, from the ISO 9660 file system used with CD-ROM media) is a disk image that contains everything that would be written to an optical disc, disk sector by disc sector, including the optical disc file system. ...

s available for burning to CD or DVD. While open source operating systems can be used for free, some commercial software, such as

Windows To Go Windows To Go is a feature in Windows 8 Enterprise, Windows 8.1 Enterprise, Windows 10 Education and Windows 10 Enterprise versions prior to the May 2020 update, that allows the system to boot and run from certain USB mass storage devices such ...

requires a license to use. Many live CDs are used for data recovery, computer forensics,

disk imaging A disk image, in computing, is a computer file containing the contents and structure of a disk volume or of an entire data storage device, such as a hard disk drive, tape drive, floppy disk, optical disc, or USB flash drive. A disk image is usua ...

, system recovery and malware removal. The Tails operating system is aimed at preserving privacy and anonymity of its users, allowing them to work with sensitive documents without leaving a record on a computer's hard drive.

History

All computers except the earliest digital computers are built with some form of minimal built-in loader, which loads a program or succession of programs from a storage medium, which then operate the computer. Initially a read-only medium such as punched tape or punched cards was used for initial program load. With the introduction of inexpensive read-write storage, read-write floppy disks and hard disks were used as boot media. After the introduction of the

audio Audio most commonly refers to sound, as it is transmitted in signal form. It may also refer to: Sound * Audio signal, an electrical representation of sound *Audio frequency, a frequency in the audio spectrum * Digital audio, representation of sou ...

compact disc The compact disc (CD) is a Digital media, digital optical disc data storage format that was co-developed by Philips and Sony to store and play digital audio recordings. In August 1982, the first compact disc was manufactured. It was then rele ...

, it was adapted for use as a medium for storing and distributing large amounts of computer data. This data may also include application and operating-system software, sometimes packaged and archived in compressed formats. Later, it was seen to be convenient and useful to boot the computer directly from compact disc, often with a minimal working system to install a full system onto a hard drive. While there are read-write optical discs, either mass-produced read-only discs or write-once discs were used for this purpose. The first Compact Disc drives on personal computers were generally much too slow to run complex operating systems; computers were not designed to boot from an

optical disc In computing and optical disc recording technologies, an optical disc (OD) is a flat, usually circular disc that encodes binary data (bits) in the form of pits and lands on a special material, often aluminum, on one of its flat surfaces. ...

. When operating systems came to be distributed on compact discs, either a

boot floppy A boot disk is a removable digital data storage medium from which a computer can load and run ( boot) an operating system or utility program. The computer must have a built-in program which will load and execute a program from a boot disk meeting ...

or the CD itself would boot specifically, and only, to install onto a hard drive. Early examples of operating systems which could be booted directly from CD-ROM are the FM Towns OS, and the Desktop-VMS distribution of VMS, both of which were first released in 1989.

Linux

Although early developers and users of distributions built on top of the

Linux kernel The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU ope ...

could take advantage of cheap optical disks and rapidly declining prices of CD drives for personal computers, the Linux distribution CDs or "distros" were generally treated as a collection of installation packages that would first need to be permanently installed to hard disks on the target machine. However, in the case of these distributions built on top of the Linux kernel, the free operating system was meeting resistance in the consumer market because of the perceived difficulty, effort, and risk involved in installing an additional partition on the hard disk, in parallel with an existing operating system installation. The term "live CD" was coined because, after typical PC RAM was large enough and 52x speed CD drives and CD burners were widespread among PC owners, it finally became convenient and practical to boot the kernel and run

X11 The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X provides the basic framework for a GUI environment: drawing and moving windows on the display device and interacting wi ...

, a window manager and GUI applications directly from a CD without disturbing the OS on the hard disk. This was a new and different situation for Linux than other operating systems, because the updates/upgrades were being released so quickly, different distributions and versions were being offered online, and especially because users were burning their own CDs. The first

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...

-based 'Live CD' was

Yggdrasil Linux Yggdrasil Linux/GNU/X, or LGX (pronounced ''igg-drah-sill''), is an early Linux distribution developed by Yggdrasil Computing, Incorporated, a company founded by Adam J. Richter in Berkeley, California. Yggdrasil was the first company to creat ...

first released in beta form 1992~1993 (ceased production in 1995), though in practice its functionality was hampered due to the low throughput of contemporary CD-ROM drives.

DemoLinux DemoLinux was one of the first Live CD Linux distributions. It was created by Roberto Di Cosmo, Vincent Balat and Jean-Vincent Loddo, in 1998. The DemoLinux CD was created to make it possible to use Linux without having to install it on the har ...

, released in 1998, was the first Linux distribution specially designed as a live CD. The

Linuxcare Linuxcare is an American IT services company founded in San Francisco in 1998 by Dave Sifry, Arthur Tyde and Dave LaDuke. The company's initial goal was to be "the 800 number for Linux" and operate 24 hours a day. Due to the dot-com bubble of the e ...

bootable business card A bootable business card (BBC) is a CD-ROM that has been cut, pressed, or molded to the size and shape of a business card (designed to fit in a wallet or pocket). Alternative names for this form factor include "credit card", "hockey rink", and " ...

, first released in 1999, was the first Live CD to focus on system administration, and the first to be distributed in the bootable business card form factor. ,

Finnix Finnix is a Debian-based Live CD operating system, developed by Ryan Finnie and intended for system administrators for tasks such as filesystem recovery, network monitoring and OS installation. Finnix is a relatively small distribution, with an ...

(first released in 2000) is the oldest Live CD still in production. Knoppix, a Debian-derived Linux distribution, was released in 2003, and found popularity as both a

rescue disk In computing, data recovery is a process of retrieving deleted, inaccessible, lost, corrupted, damaged, or formatted data from secondary storage, removable media or files, when the data stored in them cannot be accessed in a usual way. The dat ...

system and as a primary distribution in its own right. Since 2003, the popularity of live CDs has increased substantially, partly due t
Linux Live scripts
and

remastersys remastersys is a free and open-source program for Debian, Ubuntu-based, Linux Mint or derivative software systems that can: * Create a customized Live CD/Live USB (a remaster) of Debian and its derivatives. * Back up an entire system, including u ...

, which made it very easy to build customized live systems. Most of the popular Linux distributions now include a live CD variant, which in some cases is also the preferred installation medium.

Uses

Live CD of Trisquel 5.0 Live CDs are made for many different uses. Some are designed to demonstrate or "test drive" a particular operating system (usually Linux or another free or open source operating system). Software can be tested, or run for a particular single use, without interfering with system setup. Data on a system which is not functioning normally due to operating system and software issues can be made available; for example, data can be recovered from a machine with an active virus infection without the virus process being active and causing more damage, and the virus can be removed with its defences against removal bypassed. Although some live CDs can load into memory to free the optical drive for other uses, loading the data from a CD-ROM is still slower than a typical hard drive boot, so this is rarely the default with large live CD images, but for smaller live CD images loading the filesystem directly into RAM can provide a significant performance boost, as RAM is much faster than a hard drive, and uses less power. Experienced users of the operating system may also use a live CD to determine whether and to what extent a particular operating system or version is compatible with a particular hardware configuration and certain peripherals, or as a way to know beforehand which computer or peripheral will work before buying. A live CD can be used to troubleshoot hardware, especially when a hard drive fails, and more generally as a

recovery disc The terms Recovery disc (or Disk), Rescue Disk/Disc and Emergency Disk all refer to a capability to boot from an external device, possibly a thumb drive, that includes a self-running operating system: the ability to be a boot disk/Disc that runs i ...

in case of problems. Some live CDs can save user-created files in a Windows partition, a USB drive, a network drive, or other accessible media. Live backup CDs can create an image of drives, and back up files, without problems due to open files and inconsistent sets. A few additional uses include: * installing a Linux distribution to a hard drive * computer forensics * Virus scanning and Malware removal * system repair and

restoration Restoration is the act of restoring something to its original state and may refer to: * Conservation and restoration of cultural heritage ** Audio restoration ** Film restoration ** Image restoration ** Textile restoration * Restoration ecology ...

* testing new versions of software * listing & testing hardware *

Internet kiosk An interactive kiosk is a computer terminal featuring specialized hardware and software that provides access to information and applications for communication, commerce, entertainment, or education. By 2010, the largest bill pay kiosk network ...

s and public computers, which can be brought back to their original state by a reboot * high security/non-invasive environment for a guest * cracking, stealing, and changing passwords * network security testing * being the primary or backup operating system for any computer * quick and simple clustering of computers * playing video games or running applications that require a different operating system * providing a secure server platform where crucial files cannot be permanently altered * providing a secure, reliable platform for the performance of high-vulnerability tasks such as

internet banking Online banking, also known as internet banking, web banking or home banking, is an electronic payment system that enables customers of a bank or other financial institution to conduct a range of financial transactions through the financial insti ...

; * Bypassing

parental controls Parental controls are features which may be included in digital television services, computers and video games, mobile devices and software that allow parents to restrict the access of content to their children. These controls were created to ...

and other restrictions Several live CDs are dedicated to specific type of applications according to the requirements of thematic user communities. These CDs are tailored to the needs of the applications in subject including general knowledge, tutorial, specifications and trial data too. Some of these topics covers sub topics, e.g. IT administration breaks down to firewall, rescue, security, etc. type of live CDs. In some cases a particular Live DVD covers more than one topic.

Software appliances

Live CD of Fedora 11 Packaging a

software appliance A software appliance is a software application combined with just enough operating system (JeOS) to run optimally on industry-standard hardware (typically a server) or in a virtual machine. It is a software distribution or firmware that impleme ...

as an installable live CD, or live ISO, can often be beneficial as a single image can run on both real hardware and on most types of virtual machines. This allows developers to avoid the complexities involved in supporting multiple incompatible

virtual machine In computing, a virtual machine (VM) is the virtualization/emulation of a computer system. Virtual machines are based on computer architectures and provide functionality of a physical computer. Their implementations may involve specialized hardw ...

images formats and focus on the lowest common denominator instead. Typically after booting the machine from the live CD, the appliance either runs in non-persistent demo mode or installs itself, at the user's request, to an available storage device.

Mounting without burning

The files on a live CD

can be accessed in

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

with a

disk image emulator Virtual disk and virtual drive are software components that emulate an actual disk storage device. Virtual disks and virtual drives are common components of virtual machines in hardware virtualization, but they are also widely used for various p ...

such as

Daemon Tools DAEMON Tools is a virtual drive and optical disc authoring program for Microsoft Windows and Mac OS. Overview DAEMON tools was originally a successor of ''Generic SafeDisc emulator'' and incorporated all of its features. The program claims ...

, or in

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ...

variants by mounting a

loop device In Unix-like operating systems, a loop device, vnd (vnode disk), or lofi (loop file interface) is a pseudo-device that makes a computer file accessible as a block device. Before use, a loop device must be connected to an extant file in the file sy ...

. Later versions of Windows (i.e. Windows 8 and later), and software available for earlier versions, allow an ISO to be mounted as a volume. After mounting the live CD's filesystem, software on the live CD can be run directly, without booting it, by

chroot A chroot on Unix and Unix-like operating systems is an operation that changes the apparent root directory for the current running process and its children. A program that is run in such a modified environment cannot name (and therefore normall ...

ing into the mounted filesystem. A live CD ISO image can also be mounted by

Virtual Machine In computing, a virtual machine (VM) is the virtualization/emulation of a computer system. Virtual machines are based on computer architectures and provide functionality of a physical computer. Their implementations may involve specialized hardw ...

software such as

VirtualBox Oracle VM VirtualBox (formerly Sun VirtualBox, Sun xVM VirtualBox and Innotek VirtualBox) is a type-2 hypervisor for x86 virtualization developed by Oracle Corporation. VirtualBox was originally created by Innotek GmbH, which was acquired by S ...

and

VMware Workstation VMware Workstation Pro (known as VMware Workstation until release of VMware Workstation 12 in 2015) is a hosted (Type 2) hypervisor that runs on x64 versions of Windows and Linux operating systemshttps://kb.vmware.com/selfservice/microsites/sear ...

or can be converted to a

Live USB A live USB is a portable USB-attached external data storage device containing a full operating system that can be booted from. The term is reminiscent of USB flash drives but may encompass an external hard disk drive or solid-state drive, th ...

using SYSLINUX. Special tools can automate this process.

Features

Live CD of Mandriva 2010 During live CD initialization, a user typically may resort to using one or more boot codes to change the booting behavior. These vary from distribution to distribution but can most often be accessed upon first boot screen by one of the

function key A function key is a key on a computer or terminal keyboard that can be programmed so as to cause an operating system command interpreter or application program to perform certain actions, a form of soft key. On some keyboards/computers, function ...

s. Some live CDs come with an installation utility launchable from a desktop icon that can optionally install the system on a

hard drive A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magne ...

. Most live CDs can access the information on internal and/or external hard drives,

diskette A floppy disk or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolescent type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined wi ...

s and USB flash drives. Live CDs are usually distributed on read-only media, requiring either copying to rewriteable media (i.e. a hard drive or CD writer) or complete remastering to install additional software; however, there are exceptions. If

Puppy Linux Puppy Linux is an operating system and family of light-weight Linux distributions that focus on ease of use and minimal memory footprint. The entire system can be run from random-access memory (RAM) with current versions generally taking up abou ...

is recorded to an open

multisession Optical disc authoring, including DVD and Blu-ray Disc authoring, is the process of assembling source material—video, audio or other data—into the proper logical volume format to then be recorded ("burned") onto an optical disc (ty ...

medium, changes made during use (such as files created, programs installed, and preferences customised) are written in a new session to the boot medium persisting through subsequent boots. The term "Live CD" came to be used for any CD containing operating system and software which could be run without installation on the host computer. Operating systems which can be used live include

AmigaOS 4 AmigaOS 4 (abbreviated as OS4 or AOS4) is a line of Amiga operating systems which runs on PowerPC microprocessors. It is mainly based on AmigaOS 3.1 source code developed by Commodore, and partially on version 3.9 developed by Haage & Partne ...

, Amithlon,

AROS Aros may refer to: *Aros (Middle-earth), a river in J. R. R. Tolkien's Middle-earth legendarium * Aros, Mull, the location of Aros Castle, a ruined 13th-century castle on the Isle of Mull, Scotland *AROS Research Operating System, a free software i ...

, FreeBSD,

FreeDOS FreeDOS (formerly Free-DOS and PD-DOS) is a free software operating system for IBM PC compatible computers. It intends to provide a complete MS-DOS-compatible environment for running legacy software and supporting embedded systems. FreeDOS can ...

, classic Mac OS,

macOS macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and lapt ...

installation and repair discs,

OS/2 OS/2 (Operating System/2) is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. As a result of a feud between the two companies over how to position OS/2 r ...

, ReactOS, NetBSD, OpenBSD,

MINIX 3 Minix 3 is a small, Unix-like operating system. It is published under a BSD-3-Clause license and is a successor project to the earlier versions, Minix 1 and 2. The project's main goal is for the system to be fault-tolerant by detecting and rep ...

Plan 9 from Bell Labs Plan 9 from Bell Labs is a distributed operating system which originated from the Computing Science Research Center (CSRC) at Bell Labs in the mid-1980s and built on UNIX concepts first developed there in the late 1960s. Since 2000, Plan 9 has be ...

MorphOS MorphOS is an AmigaOS-like computer operating system (OS). It is a mixed proprietary and open source OS produced for the Pegasos PowerPC (PPC) processor based computer, PowerUP accelerator equipped Amiga computers, and a series of Freescale dev ...

, OpenSolaris, BeleniX and others based on

Solaris Solaris may refer to: Arts and entertainment Literature, television and film * ''Solaris'' (novel), a 1961 science fiction novel by Stanisław Lem ** ''Solaris'' (1968 film), directed by Boris Nirenburg ** ''Solaris'' (1972 film), directed by ...

. There are maintenance versions of Microsoft Windows bootable from CD such as

BartPE BartPE (Bart's Preinstalled Environment) is a discontinued tool that customizes Windows XP or Windows Server 2003 into a lightweight environment, similar to Windows Preinstallation Environment, which could be run from a Live CD or Live USB drive. ...

Windows PE Windows Preinstallation Environment (also known as Windows PE and WinPE) is a lightweight version of Windows used for the deployment of PCs, workstations, and servers, or troubleshooting an operating system while it is offline. It is intended t ...

, and

Microsoft Diagnostics and Recovery Toolset Microsoft Desktop Optimization Pack (MDOP) is a suite of utilities for Microsoft Windows customers who have subscribed to Microsoft Software Assurance program. It aims at bringing easier manageability and monitoring of enterprise desktops, emerg ...

(DaRT), previously known as Emergency Repair Disk Commander (ERD Commander). The first personal computer operating system on a CD to support "live" operations might have been the

AmigaOS AmigaOS is a family of proprietary native operating systems of the Amiga and AmigaOne personal computers. It was developed first by Commodore International and introduced with the launch of the first Amiga, the Amiga 1000, in 1985. Early versions ...

, which could be booted from CD on an

Amiga CDTV The CDTV (from Commodore Dynamic Total Vision, later treated as a backronym for Compact Disc Television) is a home multimedia entertainment and video game console – convertible into a full-fledged personal computer by the addition of optional ...

in 1990.. Earlier examples of live OS are of course the operating systems used from floppy, and most widely spread is

DOS DOS is shorthand for the MS-DOS and IBM PC DOS family of operating systems. DOS may also refer to: Computing * Data over signalling (DoS), multiplexing data onto a signalling channel * Denial-of-service attack (DoS), an attack on a communicat ...

. Live CD of Gentoo Linux Unlike previous operating systems on optical media, though, Linux and OS/2 "live CDs" were specifically designed to run without installation onto other media like a hard disk drive. The live CD concept was meant to promote Linux and showcase the abilities of the free, open source operating system on conventional personal computers with Microsoft Windows already installed. On a PC, a bootable Compact Disc generally conforms to the

El Torito El Torito (Spanish for "the little bull") is an American chain that serves Mexican food. El Torito operates 69 restaurants primarily in California.cloop compressed loopback driver, or

squashfs Squashfs is a compressed read-only file system for Linux. Squashfs compresses files, inodes and directories, and supports block sizes from 4 KiB up to 1 MiB for greater compression. Several compression algorithms are supported. Squashfs is ...

compressed filesystem, generally doubling effective storage capacity, although slowing application start up. The resulting environment can be quite rich: typical Knoppix systems include around 1,200 separate software packages. Live CDs have a reputation for supporting advanced auto-configuration and

plug-and-play In computing, a plug and play (PnP) device or computer bus is one with a specification that facilitates the recognition of a hardware component in a system without the need for physical device configuration or user intervention in resolving reso ...

functionality. This came out of necessity to avoid requiring the user to configure the system each time it boots and to make it easily usable by those who are new to the operating system.

Creation

A read-only file system, such as on a CD-ROM has the drawback of being unable to save any current working data. For this reason, a read-only file system is often merged with a temporary writable file system in the form of a

RAM disk Ram, ram, or RAM may refer to: Animals * A male sheep * Ram cichlid, a freshwater tropical fish People * Ram (given name) * Ram (surname) * Ram (director) (Ramsubramaniam), an Indian Tamil film director * RAM (musician) (born 1974), Dutch * ...

. Often the default Linux

directories Directory may refer to: * Directory (computing), or folder, a file system structure in which to store computer files * Directory (OpenVMS command) * Directory service, a software application for organizing information about a computer network's ...

"/home" (containing users' personal files and

configuration file In computing, configuration files (commonly known simply as config files) are files used to configure the parameters and initial settings for some computer programs. They are used for user applications, server processes and operating system ...

s) and "/var" (containing variable

data In the pursuit of knowledge, data (; ) is a collection of discrete values that convey information, describing quantity, quality, fact, statistics, other basic units of meaning, or simply sequences of symbols that may be further interpreted ...

) are kept in ramdisk, because the system updates them frequently. Puppy Linux and some other live CDs allow a configuration and added files to be written and used in later sessions. In modern live CDs, a read-only file system is merged with a

RAM drive Ram, ram, or RAM may refer to: Animals * A male sheep * Ram cichlid, a freshwater tropical fish People * Ram (given name) * Ram (surname) * Ram (director) (Ramsubramaniam), an Indian Tamil film director * RAM (musician) (born 1974), Dutch * ...

using

transparent Transparency, transparence or transparent most often refer to: * Transparency (optics), the physical property of allowing the transmission of light through a material They may also refer to: Literal uses * Transparency (photography), a still, ...

techniques such as

UnionFS Unionfs is a filesystem service for Linux, FreeBSD and NetBSD which implements a union mount for other file systems. It allows files and directories of separate file systems, known as branches, to be transparently overlaid, forming a single coher ...

AuFS aufs (short for advanced multi-layered unification filesystem) implements a union mount for Linux file systems. The name originally stood for AnotherUnionFS until version 2. Developed by Junjiro Okajima in 2006, aufs is a complete rewrite of t ...

or EWF. Boot loaders like syslinux can boot ISO files from USB memory devices. Live CDs have to be able to detect and use a wide variety of hardware (including

network card A network interface controller (NIC, also known as a network interface card, network adapter, LAN adapter or physical network interface, and by similar terms) is a computer hardware component that connects a computer to a computer network. Ear ...

graphic card A graphics card (also called a video card, display card, graphics adapter, VGA card/VGA, video adapter, display adapter, or mistakenly GPU) is an expansion card which generates a feed of output images to a display device, such as a computer mo ...

s etc.) in realtime, often using facilities such as

udev udev (userspace ) is a device manager for the Linux kernel. As the successor of devfsd and hotplug, udev primarily manages device nodes in the directory. At the same time, udev also handles all user space events raised when hardware devices ...

hotplug Hot swapping is the replacement or addition of components to a computer system without stopping, shutting down, or rebooting the system; hot plugging describes the addition of components only. Components which have such functionality are said ...

, hal, udisk etc.. which are a common part of all distributions based on

2.6.

References

External links

Bootable CDROM HowTo

Linux Live scripts

Pondering Live CDs
- A BSD perspective on the concept of Live CDs {{Operating System Software appliances