“If you put an infinite number of monkeys at typewriters, eventually one will bash out the script for Hamlet.” (One may also hypothesize a small number of monkeys and a very long period of time.) This theorem asserts nothing about the intelligence of the one random monkey that eventually comes up with the script (and note that the mob will also type out all the possible incorrect versions of Hamlet). It may be referred to semi-seriously when justifying a brute force method; the implication is that, with enough resources thrown at it, any technical challenge becomes a one-banana problem. This argument gets more respect since Linux justified the bazaar mode of development.

Other hackers maintain that the Infinite-Monkey Theorem cannot be true — otherwise Usenet would have reproduced the entire canon of great literature by now.

In mid-2002, researchers at Plymouth Univesity in England actually put a working computer in a cage with six crested macaques. The monkeys proceeded to bash the machine with a rock, urinate on it, and type the letter S a lot (later, the letters A, J, L, and M also crept in). The results were published in a limited-edition book, Notes Towards The Complete Works of Shakespeare. A researcher reported: “They were quite interested in the screen, and they saw that when they typed a letter, something happened. There was a level of intention there.” Scattered field reports that there are AOL users this competent have been greeted with well-deserved skepticism.

This theorem has been traced to the mathematiciamn Émile Borel in 1913, and was first popularized by the astronomer Sir Arthur Eddington. It became part of the idiom of techies via the classic SF short story Inflexible Logic by Russell Maloney, and many younger hackers know it through a reference in Douglas Adams's Hitchhiker's Guide to the Galaxy. Some other references have been collected on the Web. On 1 April 2000 the usage acquired its own Internet standard, RFC2795 (Infinite Monkey Protocol Suite).