Clone (computing)

Clones and remakes are created for reasons including competition, standardization, availability across platforms, and as homage.

The use of the term "PC clone" to describe IBM PC compatible computers fell out of use in the 1990s; the class of machines it now describes are simply called PCs, but the early use of the term "clone" usually implied a higher level of compatibility with the original IBM PC than "PC-Compatible", with (often Taiwanese) clones of the original circuit (and possibly ROMs) the most compatible (in terms of software they would run and hardware tests they would pass), while "legitimate" new designs such as the Sanyo MBC-550 and Data General/One, while not infringing on copyrights and adding innovations, tended to fail some compatibility tests strongly dependent upon detailed hardware compatibility (such as ability to run Microsoft Flight Simulator, or any software that bypassed the standard software interrupts and directly accessed hardware at the expected pre-defined locations, or—in the case of the MBC-550 for example—wrote diskettes which could not be directly interchanged with standard IBM PCs).

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 software cloning may include circumventing undesirable licensing fees, acquiring knowledge about the features of the system or creating an interoperable alternative for an unsupported platform.

In the United States, the case of Lotus v. Borland allows the functionality of a program to be cloned so long as copyright in the code and interface is not infringed.

A good share of software remakes are fangames of computer games and game engine recreation made by the fan community as part of retrogaming, to address e.g. compatibility issues or non-availability of the original, e.g. a shutdown server gets substituted with a server emulator.

Since the 2000s there has been an increasing number of commercial remakes of classical games by the original developer or publisher for current platforms as the digital distribution lowers the investment risk for niche releases.

Additionally, the cloned environment may be modified at its inception due to configuration changes or data subsetting.

Cloning software replicates the operating system, drives, software and patches of one computer for a variety of purposes, including setting up multiple computers, hard drive upgrades, and system recovery in the event of disk failure or corruption.