In computing, Xyzzy is sometimes used as a metasyntactic variable or as a video game cheat code. Xyzzy comes from the Colossal Cave Adventure computer game, where it is the first "magic word" that most players encounter (others include "plugh" and "plover"). Origin Modern usage is primarily from one of the earliest computer games, Colossal Cave Adventure, in which the idea is to explore a cave with many rooms, collecting the treasures found there. By typing "xyzzy" at the appropriate time, the player could move instantly between two otherwise distant points. As Colossal Cave Adventure was both one of the first adventure games and one of the first interactive fiction pieces, hundreds of later interactive fiction games included responses to the command "xyzzy" in tribute. The origin of the word "xyzzy" has been the subject of debate. According to Ron Hunsinger, the sequence of letters "XYZZY" has been used as a mnemonic to remember the process for computing cross products. Will Crowther, the author of Colossal Cave Adventure, states that he was unaware of the mnemonic, and that he "made it up from whole cloth" when writing the game. Usage Operating systems Xyzzy has been implemented as an undocumented no-op command on several operating systems; in the 16-bit version of Data General's AOS, for example, it would typically respond "Nothing happens", just as the game did if the magic was invoked at the wrong spot or before a player had performed the action that enabled the word. The 32-bit version, AOS/VS, would respond "Twice as much happens". On several computer systems from Sun Microsystems, the command "xyzzy" is used to enter the interactive shell of the U-Boot bootloader. Early versions of Zenith Z-DOS (a re-branded variant of MS-DOS 1.25) had the command "xyzzy" which took a parameter of "on" or "off". Xyzzy by itself would print the status of the last "xyzzy on" or "xyzzy off" command. When booting a Cr-48 from developer mode, when the screen displays the "sad laptop" image, typing "xyzzy" produces a joke Blue Screen of Death. According to Brantley Coile, the Cisco PIX firewall had a xyzzy command that simply said "Nothing happens." He also put the command into the Coraid VSX to escape the CLI and get into the shell. It would announce "Foof! You are in a directory. There are files here." The new California Coraid management made the developers change the string