From the custom of the Easter egg hunt observed in Western Nations and many parts of Europe, Easter eggs are hidden messages or features which may appear in movies, DVDs, books, on CDs, or in computer programs.

Computer-related Easter eggs

In computing, Easter eggs are messages, graphics, sound effects, or an unusual change in program behaviour, that occur in a program in response to some undocumented set of commands, mouse clicks, keystrokes or other similar stimuli intended as a joke or to display program credits. See also Undocumented feature. A former use of the term Easter egg was to describe a message hidden in the object code of a program as a joke, intended to be found by persons disassembling or browsing the code.

One well-known early Easter egg found in a couple of Unix operating systems caused them to respond to the command "make love" with "not war?". Many personal computers have much more elaborate eggs hidden in ROM, including lists of the developers' names, political exhortations, snatches of music, and (in one case) images of the entire development team. Microsoft Excel has a well-known car racing game embedded inside. The Palm operating system has elaborately hidden animations and other surprises.

Whilst computer-related Easter eggs are often found in software, occasionally they can exist in hardware or firmware of certain devices. On some PCs, the BIOS ROM contains Easter eggs. Perhaps the most famous example of a hardware Easter egg is in the HP ScanJet 5P, where the device will play the Ode to Joy by varying the stepper motor speed if you power the device up with the scan button depressed.

Video game Easter eggs

Easter eggs in computer games and other video games are distinguished from cheat codes which allow you to cheat - see Minesweeper for an example. The first known video game to feature an Easter egg was the classic Atari game Adventure, in which a designer's name would be displayed if the player used a certain item in a certain location in the game. For a more recent example, Grand Theft Auto: Vice City featured a literal Easter egg hidden inside the upper floors of a normally inaccessible skyscraper. The tradition of including Easter eggs in video games has created small sections of gaming fandom that are as devoted to finding Easter eggs as they are to playing games as they are intended.

Based on information from the Jargon File.

Compact disc and DVD Easter eggs

Some compact discs include hidden features which may be called Easter eggs, such as screensavers for a computer which can only be accessed if the CD is played in a CD-ROM drive, or hidden music tracks appended at the end of the disc, or prepended to the beginning (before the first track). An example of the former is the album The World According To Gessle by Roxette's Per Gessle: at the end of the disc an unlisted acoustic version of Kix appears, sung in Elvis style. An example of the latter (which is somewhat more rare) is the album Factory Showroom by They Might Be Giants where a short song called "Token Back to Brooklyn" can be heard when the CD is "rewound" to approximately negative one minute and twenty seconds on track one.

Even more prevalent are Easter eggs in DVD releases of movies; these are often in the form of hidden trailers, documentaries, or deleted scenes, and are accessed by manipulation of the disc's interactive menus. An example is the DVD for The Abyss, which has at least nine Easter eggs, including at least three different trailers for Aliens and two for True Lies, two other James Cameron films. More elaborate eggs include that for Memento, which plays the scenes of the movie sorted into chronological order. In order to distinguish between different editions of the same film, some distributors have taken to listing Easter eggs in lists of "extra features" on the packaging and promotional material; some do not consider Easter eggs advertised in this way to be true Easter eggs.

Easter eggs in movies and fiction

Various forms of fiction, particularly movies, have a long-standing tradition for hiding references to people or previous works, which could also be considered a form of Easter egg, although they probably predate this use of the term. Often, such references are homages to other writers or directors, but sometimes they are more like in-jokes referring to the previous work or private life of a member of the cast or crew in some way. Such references usually take the form of incidental details such as the name of a minor character or location, or text written on a prop that is not significant to the plot. For instance, in the original Star Wars film, the characters visit "cell block one-one-thirty-eight" on the Death Star - a reference to THX-1138, which was director George Lucas' first movie.

External links

• Easter Egg Archive (http://www.eeggs.com) – Up-to-date lists and discussions of Easter eggs, both digital and found in art, books, etc.
• Egg Heaven 2000 (http://www.eggheaven2000.com/) – Computer Easter Eggs Database
• DVD Easter Eggs (http://www.dvdeastereggs.com/) – Lists many Easter eggs in DVDs