Fork (software development)

In software engineering, a project fork happens when developers take a copy of source code from one software package and start independent development on it, creating a distinct and separate piece of software. The term often implies not merely a development branch, but a split in the developer community, a form of schism.

Free and open-source software is that which, by definition, may be forked from the original development team without prior permission without violating copyright law. However, licensed forks of proprietary software (e.g. Unix) also happen.

Etymology

The word fork stems from the Latin word furca, meaning a "fork or similarly shaped instrument." "Fork" in the meaning of "to divide in branches, go separate ways" has been used as early as the 14th century. In the software environment, the word evokes the fork system call, which causes a running process to split itself into two (almost) identical copies that (typically) diverge to perform different tasks.

Fork

As a piece of cutlery or kitchenware, a fork is a tool consisting of a handle with several narrow tines on one end. The fork is a primarily Western utensil, whereas in East Asia chopsticks have been more prevalent. Today, forks are increasingly available throughout East Asia. The usually metal utensil is used to lift food to the mouth or to hold ingredients in place while they are being cut by a knife. Food can be lifted either by spearing it on the tines, or by holding it on top of the tines, which are often curved slightly. A fork is shaped in the form of a trident but curved at the joint of the handle to the points.

Early history of forks is obscure, as a kitchen and dining utensil it's generally believed to have originated in the Roman Empire, as proved by archaeological evidences. The personal table fork most likely originated in the Eastern Roman, or Byzantine, Empire. Its use spread to what is now the Middle East during the first millennium CE and then spread into southern Europe during the second millennium. It did not become common in northern Europe until the 18th century and was not common in North America until the 19th century.

Fork (file system)

In a computer file system, a fork is a set of data associated with a file system object. File systems without forks only allow a single such set of data for the contents, while file systems with forks allow multiple such contents. Every non-empty file must have at least one fork, often of default type, and depending on the file system, a file may have one or more other associated forks, which in turn may contain primary data integral to the file, or just metadata. Unlike extended attributes, a similar file system feature which is typically of fixed size, forks can be of variable size, possibly even larger than the file's primary data fork. The size of a file is the sum of the sizes of each fork. Forks are also known as streams, since they are of variable size (unlike fixed size metadata), but this differs from other uses of "stream" to mean "data available over time, potentially infinite".

Alternatives

On file systems without forks, one may instead use multiple separate files that are associated with each other, particularly sidecar files for metadata. However, the connection between these files is not automatically preserved by the file system, and must instead be handled by each program that works on files. Another alternative is a container file, which stores additional data within a given file format, or an archive file, which allows storing several files and metadata within a file (within a single fork). This requires that programs process the container file or archive file, rather than the file system handling forks. These alternatives require additional work by programs using the data, but benefit from portability to file systems that do not support forks.

Fork (chess)

In chess, a fork is a tactic whereby a single piece makes two or more direct attacks simultaneously. Most commonly two pieces are threatened, which is also sometimes called a double attack. The attacker usually aims to gain material by capturing one of the opponent's pieces. The defender often finds it difficult to counter two or more threats in a single move. The attacking piece is called the forking piece; the pieces attacked are said to be forked. A piece that is defended can still said to be forked if the forking piece has a lower value.

Besides attacking pieces, a target of a fork can be a direct mating threat (for example, attacking an unprotected knight while simultaneously setting up a battery of queen and bishop to threaten mate). Or a target can be an implied threat (for example, a knight may attack an unprotected piece while simultaneously threaten to fork queen and rook).

Forks are often used as part of a combination which may involve other types of chess tactics as well.

Software (novel)

Software is a 1982 cyberpunk science fiction novel written by Rudy Rucker. It won the first Philip K. Dick Award in 1983. The novel is the first book in Rucker's Ware Tetralogy, and was followed by a sequel, Wetware, in 1988.

Plot summary

Software introduces Cobb Anderson as a retired computer scientist who was once tried for treason for figuring out how to give robots artificial intelligence and free will, creating the race of boppers. By 2020, they have created a complex society on the Moon, where the boppers developed because they depend on super-cooled superconducting circuits. In that year, Anderson is a pheezer — a freaky geezer, Rucker's depiction of elderly Baby Boomers — living in poverty in Florida and terrified because he lacks the money to buy a new artificial heart to replace his failing, secondhand one.

As the story begins, Anderson is approached by a robot duplicate of himself who invites him to the Moon to be given immortality. Meanwhile, the series' other main character, Sta-Hi Mooney the 1st — born Stanley Hilary Mooney Jr. — a 25-year-old cab driver and "brainsurfer", is kidnapped by a gang of serial killers known as the Little Kidders who almost eat his brain. When Anderson and Mooney travel to the Moon together at the boppers' expense, they find that these events are closely related: the "immortality" given to Anderson turns out to be having his mind transferred into software via the same brain-destroying technique used by the Little Kidders.

Software (development cooperation)

See also

Further reading

Software (disambiguation)

Software usually refers to instructions for computer hardware to execute.

Software may also refer to: