In
computingComputing is usually defined as the activity of using and developing computer technology, computer hardware and software. It is the computer-specific part of information technology...
, a
clone is a
hardwareA personal computer is made up of multiple physical components of computer hardware, upon which can be installed an operating system and a multitude of software to perform the operator's desired functions.-Typical PC hardware:...
or software system that is designed to mimic another system.
CompatibilityA family of computer models is said to be compatible if certain software that runs on one of the models can also be run on all other models of the family. The computer models may differ in performance, reliability or some other characteristic...
with the original system is usually the explicit purpose of cloning hardware or low-level software such as
operating systemAn operating system is an interface between hardware and user which is responsible for the management and coordination of activities and the sharing of the resources of the computer that acts as a host for computing applications run on the machine. As a host, one of the purposes of an operating...
s. Application software can be cloned simply by providing similar functionality (all
word processorA word processor is a computer application used for the production of any sort of printable material....
s have the same basic purpose), but may also be designed to support specific
file formatA file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...
s (e.g.,
OpenOffice.orgOpenOffice.org , commonly known as OpenOffice, is an office application suite available for a number of different computer operating systems. It is distributed as free software and written using its own GUI toolkit...
is intended to supplant
Microsoft OfficeMicrosoft Office is an office suite of interrelated desktop applications, servers and services for the Microsoft Windows and Mac OS X operating systems. Microsoft Office was introduced by Microsoft in 1989 for Mac OS, with a version for Windows in 1990...
).
Clones are created for various reasons, including competition, standardization, and availability across platforms.
When IBM announced the
IBM PCThe IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...
in 1981, other companies such as
CompaqCompaq Computer Corporation was an American personal computer company founded in 1982, and is now a brand name of Hewlett-Packard.The company was formed by Rod Canion, Jim Harris and Bill Murto — former Texas Instruments senior managers...
decided to offer clones of the PC as a legal reimplementation from the PC's documentation or
reverse engineeringReverse engineering is the process of discovering the technological principles of a device, object or system through analysis of its structure, function and operation...
.
In
computingComputing is usually defined as the activity of using and developing computer technology, computer hardware and software. It is the computer-specific part of information technology...
, a
clone is a
hardwareA personal computer is made up of multiple physical components of computer hardware, upon which can be installed an operating system and a multitude of software to perform the operator's desired functions.-Typical PC hardware:...
or software system that is designed to mimic another system.
CompatibilityA family of computer models is said to be compatible if certain software that runs on one of the models can also be run on all other models of the family. The computer models may differ in performance, reliability or some other characteristic...
with the original system is usually the explicit purpose of cloning hardware or low-level software such as
operating systemAn operating system is an interface between hardware and user which is responsible for the management and coordination of activities and the sharing of the resources of the computer that acts as a host for computing applications run on the machine. As a host, one of the purposes of an operating...
s. Application software can be cloned simply by providing similar functionality (all
word processorA word processor is a computer application used for the production of any sort of printable material....
s have the same basic purpose), but may also be designed to support specific
file formatA file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...
s (e.g.,
OpenOffice.orgOpenOffice.org , commonly known as OpenOffice, is an office application suite available for a number of different computer operating systems. It is distributed as free software and written using its own GUI toolkit...
is intended to supplant
Microsoft OfficeMicrosoft Office is an office suite of interrelated desktop applications, servers and services for the Microsoft Windows and Mac OS X operating systems. Microsoft Office was introduced by Microsoft in 1989 for Mac OS, with a version for Windows in 1990...
).
Clones are created for various reasons, including competition, standardization, and availability across platforms.
Hardware
When IBM announced the
IBM PCThe IBM Personal Computer, commonly known as the IBM PC, is the original version and progenitor of the IBM PC compatible hardware platform. It is IBM model number 5150, and was introduced on August 12, 1981...
in 1981, other companies such as
CompaqCompaq Computer Corporation was an American personal computer company founded in 1982, and is now a brand name of Hewlett-Packard.The company was formed by Rod Canion, Jim Harris and Bill Murto — former Texas Instruments senior managers...
decided to offer clones of the PC as a legal reimplementation from the PC's documentation or
reverse engineeringReverse engineering is the process of discovering the technological principles of a device, object or system through analysis of its structure, function and operation...
. Because most of the components, except the PC's
BIOSIn IBM PC Compatible computers, the basic input/output system , also known as the System BIOS, is a de facto standard defining a firmware interface. The BIOS is boot firmware, designed to be the first code run by a PC when powered on...
, were publicly available, all Compaq had to do was reverse-engineer the BIOS. The result was a machine with better value than the archetypes that the machines resembled. The use of the term "PC clone" to describe
IBM PC compatibleIBM PC compatible computers are those generally similar to the original IBM PC, XT, and AT. Such computers used to be referred to as PC clones, or IBM clones since they almost exactly duplicated all the significant features of the PC architecture, facilitated by various manufacturers' ability to...
computers fell out of use in the 1990s; the class of machines it now describes are simply called PCs, Intel machines, or even
WintelWintel is portmanteau of Windows and Intel. It usually means a computer based on an Intel x86 compatible processor and running the Microsoft Windows operating system.-Background:...
machines.
While the term has fallen mostly into commercial disuse, the term
clone for PCs still applies to a PC made to entry-level or above standard (at the time it was made) which bears no commercial branding (e.g., Acer, IBM, HP, Dell). This includes, but is not limited to, PCs assembled by home users or Corporate IT Departments. (See also
White box (computer hardware)In computer hardware, a white box is a personal computer or server assembled from off-the-shelf parts. The term is applied to systems assembled by small system integrators, and to homebuilt computer systems assembled by end users from parts purchased separately at retail...
.)
Distinct from clones are home computer remakes. Clones are made during a product's initial commercial run, intentionally competing with the original. Remakes are revivals of old, obsolete, or discontinued models.
Software
Software can be cloned by reverse engineering or legal reimplementation from documentation or other sources, or by observing a program's appearance and behavior. The reasons for cloning may include circumventing undesirable licensing fees or acquiring knowledge about the features of the system. In the United States, the case of
Lotus v. BorlandLotus Development Corporation v. Borland International, Inc., 516 U.S. 233 , is a United States Supreme Court case that tested the extent of software copyright...
allows programmers to clone the public functionality of a program without infringing its
copyrightCopyright is a form of intellectual property that gives the author of an original work exclusive right for a certain time period in relation to that work, including its publication, distribution and adaptation, after which time the work is said to enter the public domain...
.