:virtual Friday: /n./ (also `logical Friday') The last day before an extended weekend, if that day is not a `real' Friday. For example, the U.S. holiday Thanksgiving is always on a Thursday. The next day is often also a holiday or taken as an extra day off, in which case Wednesday of that week is a virtual Friday (and Thursday is a virtual Saturday, as is Friday). There are also `virtual Mondays' that are actually Tuesdays, after the three-day weekends associated with many national holidays in the U.S.

:virtual reality: /n./ 1. Computer simulations that use 3-D graphics and devices such as the Dataglove to allow the user to interact with the simulation. See {cyberspace}. 2. A form of network interaction incorporating aspects of role-playing games, interactive theater, improvisational comedy, and `true confessions' magazines. In a virtual reality forum (such as Usenet's alt.callahans newsgroup or the {MUD} experiments on Internet), interaction between the participants is written like a shared novel complete with scenery, `foreground characters' that may be personae utterly unlike the people who write them, and common `background characters' manipulable by all parties. The one iron law is that you may not write irreversible changes to a character without the consent of the person who `owns' it. Otherwise anything goes. See {bamf}, {cyberspace}, {teledildonics}.

:virtual shredder: /n./ The jargonic equivalent of the {bit bucket} at shops using IBM's VM/CMS operating system. VM/CMS officially supports a whole bestiary of virtual card readers, virtual printers, and other phantom devices; these are used to supply some of the same capabilities Unix gets from pipes and I/O redirection.

:virus: /n./ [from the obvious analogy with biological viruses, via SF] A cracker program that searches out other programs and `infects' them by embedding a copy of itself in them, so that they become {Trojan horse}s. When these programs are executed, the embedded virus is executed too, thus propagating the `infection'. This normally happens invisibly to the user. Unlike a {worm}, a virus cannot infect other computers without assistance. It is propagated by vectors such as humans trading programs with their friends (see {SEX}). The virus may do nothing but propagate itself and then allow the program to run normally. Usually, however, after propagating silently for a while, it starts doing things like writing cute messages on the terminal or playing strange tricks with the display (some viruses include nice {display hack}s). Many nasty viruses, written by particularly perversely minded {cracker}s, do irreversible damage, like nuking all the user's files.

In the 1990s, viruses have become a serious problem, especially among IBM PC and Macintosh users (the lack of security on these machines enables viruses to spread easily, even infecting the operating system). The production of special anti-virus software has become an industry, and a number of exaggerated media reports have caused outbreaks of near hysteria among users; many {luser}s tend to blame *everything* that doesn't work as they had expected on virus attacks. Accordingly, this sense of `virus' has passed not only into techspeak but into also popular usage (where it is often incorrectly used to denote a {worm} or even a {Trojan horse}). See {phage}; compare {back door}; see also {Unix conspiracy}.

:visionary: /n./ 1. One who hacks vision, in the sense of an Artificial Intelligence researcher working on the problem of getting computers to `see' things using TV cameras. (There isn't any problem in sending information from a TV camera to a computer. The problem is, how can the computer be programmed to make use of the camera information? See {SMOP}, {AI-complete}.) 2. [IBM] One who reads the outside literature. At IBM, apparently, such a penchant is viewed with awe and wonder.

:VMS: /V-M-S/ /n./ DEC's proprietary operating system for its VAX minicomputer; one of the seven or so environments that loom largest in hacker folklore. Many Unix fans generously concede that VMS would probably be the hacker's favorite commercial OS if Unix didn't exist; though true, this makes VMS fans furious. One major hacker gripe with VMS concerns its slowness — thus the following limerick:

There once was a system called VMS
Of cycles by no means abstemious.
It's chock-full of hacks
And runs on a VAX
And makes my poor stomach all squeamious.
— The Great Quux

See also {VAX}, {{TOPS-10}}, {{TOPS-20}}, {{Unix}}, {runic}.

:voice: /vt./ To phone someone, as opposed to emailing them or connecting in {talk mode}. "I'm busy now; I'll voice you later."