Editing Quine (computing) (section)

{{Short description|Self-replicating program}}

[[File:Java implementation of a quine program.png|thumb|300px|A quine's output is exactly the same as its source code.]]
A '''quine''' is a [[computer program]] that takes no input and produces a copy of its own [[source code]] as its only output. The standard terms for these programs in the [[computability theory]] and [[computer science]] literature are "self-replicating programs", "self-reproducing programs", and "self-copying programs".

A quine is a [[Fixed point (mathematics)|fixed point]] of an execution environment, when that environment is viewed as a [[Function (mathematics)|function]] transforming programs into their outputs. Quines are possible in any [[Turing completeness|Turing-complete]] programming language, as a direct consequence of [[Kleene's recursion theorem]]. For amusement, programmers sometimes attempt to develop the shortest possible quine in any given [[programming language]].