Multi-user software is computer software that allows access by multiple users of a computer. Time-sharing systems are multi-user systems.

Multi-User Dimension

<games> (MUD) (Or Multi-User Domain, originally "Multi-User Dungeon") A class of multi-player interactive game, accessible via the Internet or a modem. A MUD is like a real-time chat forum with structure; it has multiple "locations" like an adventure game and may include combat, traps, puzzles, magic and a simple economic system. A MUD where characters can build more structure onto the database that represents the existing world is sometimes known as a "MUSH". Most MUDs allow you to log in as a guest to look around before you create your own character. Historically, MUDs (and their more recent progeny with names of MU- form) derive from a hack by Richard Bartle and Roy Trubshaw on the University of Essex's DEC-10 in 1979. It was a game similar to the classic Colossal Cave adventure, except that it allowed multiple people to play at the same time and interact with each other. Descendants of that game still exist today and are sometimes generically called BartleMUDs. There is a widespread myth that the name MUD was trademarked to the commercial MUD run by Bartle on {British Telecom} (the motto: "You haven't *lived* 'til you've *died* on MUD!"); however, this is false - Richard Bartle explicitly placed "MUD" in the PD in 1985. BT was upset at this, as they had already printed trademark claims on some maps and posters, which were released and created the myth. Students on the European academic networks quickly improved on the MUD concept, spawning several new MUDs (VAXMUD, AberMUD, LPMUD). Many of these had associated bulletin-board systems for social interaction. Because these had an image as "research" they often survived administrative hostility to BBSs in general. This, together with the fact that Usenet feeds have been spotty and difficult to get in the UK, made the MUDs major foci of hackish social interaction there. AberMUD and other variants crossed the Atlantic around 1988 and quickly gained popularity in the US; they became nuclei for large hacker communities with only loose ties to traditional hackerdom (some observers see parallels with the growth of Usenet in the early 1980s). The second wave of MUDs (TinyMUD and variants) tended to emphasise social interaction, puzzles, and cooperative world-building as opposed to combat and competition. In 1991, over 50% of MUD sites are of a third major variety, LPMUD, which synthesises the combat/puzzle aspects of AberMUD and older systems with the extensibility of TinyMud. The trend toward greater programmability and flexibility will doubtless continue. The state of the art in MUD design is still moving very rapidly, with new simulation designs appearing (seemingly) every month. There is now a move afoot to deprecate the term MUD itself, as newer designs exhibit an exploding variety of names corresponding to the different simulation styles being explored. {UMN MUD Gopher page (gopher://spinaltap.micro.umn.edu/11/fun/Games/MUDs/Links)}. {Multi-User Dimensionlwl/mudinfo.html">U Pennsylvania MUD Web page (http://cis.upenn.edu/Multi-User Dimensionlwl/mudinfo.html)}. See also bonk/oif, FOD, link-dead, mudhead, MOO, MUCK, MUG, MUSE, chat. Usenet newsgroups: news:rec.games.mud.announce, news:rec.games.mud.admin, news:rec.games.mud.diku, news:rec.games.mud.lp, news:rec.games.mud.misc, news:rec.games.mud.tiny. (1994-08-10)

Synchronous conferencing is the formal term used in computing, in particular in computer-mediated communication, collaboration and learning, to describe technologies informally known as online chat. It is sometimes extended to include audio/video conferencing or instant messaging systems that provide a text-based multi-user chat function.

<operating system, security> (Or "logon") A unique name for each user of computer services which can be accessed by several persons. Users need to identify themselves for accounting, security, logging, and resource management. Usually a person must also enter a password in order to access a service. Once the user has logged on the operating system will often use a (short) user identifier, e.g. an integer, to refer to them rather than their user name. User names can usually be any short string of alphanumeric characters. Common choices are first name, initials, or some combination of first name, last name, initials and an arbitrary number. User names are often assigned by {system administrators} according to some local policy, or they may be chosen by the users themselves. User names are often also used as mailbox names in electronic mail addresses. (1997-03-16)

A power user is a user of computers, software and other electronic devices, who uses advanced features of computer hardware, operating systems, programs, or websites which are not used by the average user. A power user might not have extensive technical knowledge of the systems they use but is rather characterized by competence or desire to make the most intensive use of computer programs or systems.

In computing, a user agent is any software, acting on behalf of a user, which "retrieves, renders and facilitates end-user interaction with Web content". A user agent is therefore a special kind of software agent.

user identifier

<operating system> 1. (Or "uid", "user id") A number or name which is unique to a particular user of a computer or group of computers which share user information. The {operating system} uses the uid to represent the user in its data structures, e.g. the owner of a file or process, the person attempting to access a system resource etc. A user database, e.g. Unix's /etc/passwd file or NIS, maps the uid to other information about that user such as their user name, password, home directory and real name. 2. user name. (1997-03-01)