The Jargon File has this definition for clone: The Jargon File is a glossary of hacker slang. ...

1. An exact duplicate: "Our product is a clone of their product." Implies a legal reimplementation from documentation or by reverse-engineering. Also connotes lower price.
2. A shoddy, spurious copy: "Their product is a clone of our product."
3. A blatant ripoff, most likely violating copyright, patent, or trade secret protections: "Your product is a clone of my product." This use implies legal action is pending.
4. [obs.] "PC clone:" a PC-BUS/ISA or EISA-compatible 80x86-based microcomputer (this use is sometimes spelled "klone" or "PClone"). These invariably have much more bang for the buck than the IBM archetypes they resemble. This term fell out of use in the 1990s; the class of machines it describes are now simply "PCs" or "Intel machines".
5. [obs.] In the construction "Unix clone": An Operating system designed to deliver a Unix-lookalike environment without Unix license fees, or with additional "mission-critical" features such as support for real-time programming. Linux and the free BSDs killed off this product category and the term with it.
6. v. To make an exact copy of something. "Let me clone that" might mean "I want to borrow that paper so I can make a photocopy" or "Let me get a copy of that file before you mung it".

For copyright issues in relation to Wikipedia itself, see Wikipedia:Copyrights. ... A patent is a set of exclusive rights granted by a state to a person for a fixed period of time in exchange for the regulated, public disclosure of certain details of a device, method, process or substance (known as an invention) which is new, inventive and useful. ... A trade secret is a confidential practice, method, process, design, or other information used by a company to compete with other businesses. ... One of the first PCs from IBM - the IBM PC model 5150. ... It has been suggested that XT bus architecture be merged into this article or section. ... The Extended Industry Standard Architecture (in practice almost always shortened to EISA and pronounced eee-suh) is a bus standard for IBM compatible computers. ... x86 or 80x86 is the generic name of a microprocessor architecture first developed and manufactured by Intel. ... 1990 is a common year starting on Monday of the Gregorian calendar. ... Unix or UNIX is a computer operating system originally developed in the 1960s and 1970s by a group of AT&T Bell Labs employees including Ken Thompson, Dennis Ritchie, and Douglas McIlroy. ... In computing, an operating system (OS) is the system software responsible for the direct control and management of hardware and basic system operations. ... Tux, a cartoon penguin frequently featured sitting, is the official Linux mascot. ... Berkeley Software Distribution (BSD) is the UNIX derivative distributed by the University of California, Berkeley starting in the 1970s. ...

Hardware

A clone is a computer system (both hardware and software) based on another company's system and designed to be compatible with it.

When IBM came out with the IBM PC in 1981, other companies such as Compaq decided to put out a clone of the PC as a legal reimplemenatation from the PC's documentation or reverse engineering. As most of the components except the PC's BIOS were publicly available, all Compaq had to do was reverse engineer the BIOS. The result was a machine that had more bang for the buck than the archetypes that the machine resembled. The term "PC clone" fell out of use in the 1990s; the class of machines it now describes are simply called PCs or Intel machines (or even Wintel machines). International Business Machines Corporation (IBM, or colloquially, Big Blue) (NYSE: IBM) (incorporated June 15, 1911, in operation since 1888) is headquartered in Armonk, New York, USA. The company manufactures and sells computer hardware, software, and services. ... IBM PC (IBM 5150) with keyboard and green screen monochrome monitor (IBM 5151), running MS-DOS 5. ... 1981 is a common year starting on Thursday of the Gregorian calendar. ... Compaq Computer Corporation was a company producing a wide range of computer products that was formed in 1982 and existed as a standalone entity until 2002 when it was merged with Hewlett-Packard. ... Reverse engineering (RE) is the process of taking something (a device, an electrical component, a software program, etc. ... BIOS, in computing, stands for basic input/output system. ... One of the first PCs from IBM - the IBM PC model 5150. ... 1990 is a common year starting on Monday of the Gregorian calendar. ... Wintel is a colloquial, often pejorative, term used to describe desktop computers of the type commonly used in homes and businesses since the late 1980s (these are PC compatible computers running a version of Microsoft Windows). ...

Software

Software can be cloned by reverse engineering or legal reimplementation from documentation or other sources. Software such as MS-DOS's edlin line editor and the Unix operating system have been cloned. The reasons for cloning may include getting around draconian licensing fees or as a curiosity; e.g. because the programmer can. Microsofts disk operating system, MS-DOS, was Microsofts implementation of DOS, which was the first popular operating system for the IBM PC, and until recently, was widely used on the PC compatible platform. ... The EDLIN line editor was the only text editor provided with MS-DOS before version 5. ... Unix or UNIX is a computer operating system originally developed in the 1960s and 1970s by a group of AT&T Bell Labs employees including Ken Thompson, Dennis Ritchie, and Douglas McIlroy. ...

In software development the term clone can also refer to the process of duplicating an existing data set or object. There are two typical types of cloning. Shallow cloning is a simple copy of the original maintaining references to the original data set or object's references. Changes to a shallow clone will affect both the orignial and the clone. Deep cloning is a full and independent duplication of the original which will remain unchanged if the original is changed following the cloning process.