<character> An {atom} in a {character repertoire}.

	Compare with {glyph}.

	(1998-10-18)

[probably from "main store"] In some varieties of Commonwealth
	hackish, the preferred synonym for {core}.  Thus, "bringing a
	program into store" means not that one is returning
	shrink-wrapped software but that a program is being {swap}ped
	in.

	[{Jargon File}]

<data, data processing, jargon> /day't*/ (Or "raw data")
	Numbers, {characters}, {images}, or other method of recording,
	in a form which can be assessed by a human or (especially)
	input into a {computer}, stored and {processed} there, or
	transmitted on some {digital channel}.  Computers nearly
	always represent data in {binary}.

	Data on its own has no meaning, only when interpreted by some
	kind of {data processing system} does it take on meaning and
	become {information}.

	People or computers can find patterns in data to perceive
	information, and information can be used to enhance
	{knowledge}.  Since knowledge is prerequisite to wisdom, we
	always want more data and information.  But, as modern
	societies verge on {information overload}, we especially need
	better ways to find patterns.

	1234567.89 is data.

	"Your bank balance has jumped 8087% to $1234567.89" is
	information.

	"Nobody owes me that much money" is knowledge.

	"I'd better talk to the bank before I spend it, because of
	what has happened to other people" is wisdom.

	(1999-04-30)

<messaging> A model of media distribution were the bits of
	content have to be requested by the user, e.g. normal use of
	{HTTP} on the {World-Wide Web}.

	Opposite: "{push media}".

	(1997-04-10)

Common term for "computer", usually when considered at the
	hardware level.  The {Turing Machine}, an early example of
	this usage, was however neither hardware nor software, but
	only an idea.

	[Earlier use?]

	(1995-02-15)

1. Executable code, especially a "pure code" portion shared
	between multiple instances of a program running in a
	{multitasking} {operating system}.

	Compare {English}.

	2. Textual material in the mainstream sense; data in ordinary
	{ASCII} or {EBCDIC} representation (see {flat ASCII}).  "Those
	are text files; you can review them using the editor."

	These two contradictory senses confuse hackers too.

	[{Jargon File}]

	(1995-03-16)

<data, database> An area of a {database} {record}, or
	{graphical user interface} {form}, into which a particular
	item of data is entered.

	Example usage: "The telephone number field is not really a
	numerical field", "Why do we need a four-digit field for the
	year?".

	A {database} {column} is the set of all instances of a given
	field from all records in a {table}.

	(1999-04-26)

1. <hardware> A generic term for a {display device} that shows
	text and/or images on a roughly flat rectangular surface.  The
	most common type is usually refered to as a "{monitor}" and is
	based on a {cathode-ray tube}, though {flat panel} displays
	have, since around 2000, become increasingly competitive in
	price and performance.

	(2005-07-28)

	2. A {screen multiplexer} utility which lets you run multiple
	{interactive} {terminal sessions} (and {curses} programs)
	through a single terminal connection (on one {virtual
	console}, one terminal, through one {modem} link, {telnet}
	session or {xterm}).

	Screen can detach processes from one terminal and attach them
	to another.  "Auto-detach" lets you continue working after
	being disconnected and reconnected.  It supports keyboard
	driven cut and paste from any text and/or curses application
	(like {Lynx}) to any other (like {xemacs}).

	Screen comes with many {Linux} distributions and is available
	(free) on many other {Unix} {platforms}.

	(2005-07-29)

1. <hardware> {monitor}.

	2. <language> A vector of pointers to {activation records}.
	The Nth element points to the activation record containing
	variables declared at {lexical depth} N.  This allows faster
	access to variables from outer {scopes} than the alternative
	of linked activation records (but most variable accesses are
	either local or global or occasionally to the immediately
	enclosing scope).  Displays were used in some {ALGOL}
	implementations.

	(1996-02-22)

<software> Instructions for a computer in some programming
	language, often {machine language}.  The word "code" is often
	used to distinguish instructions from {data} (e.g. "The code
	is marked 'read-only'") whereas "{software}" is used in
	contrast with "{hardware}" and may consist of more than just
	code.

	(2000-04-08)

1. <character> {hash character}.

	2. <programming> {hash coding}.

	3. The preferred term for a {Perl} {associative array}.

	(1995-03-06)

<operating system> (Win2k, W2k, NT5, Windows NT 5.0) An
	{operating system} developed by {Microsoft Corporation} for
	{PCs} and {servers}, as the successor to {Windows NT 4}.0.
	Early {beta} versions were referred to as "Windows NT 5.0".
	Windows 2000 was officially released on 2000-02-17.

	Windows 2000 is most commonly used on {Intel} {x86} and
	{Pentium} processors, with a {DEC Alpha} version rumoured.
	Unlike Windows NT 4.0, Windows 2000 is not available for
	{PowerPC} or {MIPS}.

	Windows 2000's {user interface} is very similar to {Windows
	95} or Windows NT 4.0 with integrated {Internet Explorer}, or
	to {Windows 98}.

	It is available in four flavours:

	- Professional: the {client} version, meant for desktop
	{workstations}, successor to Windows NT Workstation.

	- Server: "entry-level" server, designed for small
	deployments, and departmental file, print, or {intranet}
	servers.

	- Advanced Server: high throughput, larger scale servers
	and applications, and small to medium scale {websites}.

	- Data Center Server: software for large-scale server
	{clusters} (in development as of 2000-03-14).

	New features in Windows 2000 include:

	- {Active Directory}.

	- Greatly improved built-in security mechanisms, including
	{Kerberos}-based {authentication}, {public key} support, an
	{encrypting} {file system}, and {IPsec} support.

	- Integrated {web browser} - {Internet Explorer} 5.0.

	- Integrated {web server} - {IIS} 5.0

	- Terminal services for displaying application interfaces on
	remote computers (similar to {X-Windows}).

	- File protection that prevents user programs from
	accidentally deleting or overwriting critical system files.

	- Improved hardware support, including {Plug-and-Play}, {DVD},
	{IEEE-1394} (FireWire), {USB}, {infra-red}, {PCMCIA}, {ACPI},
	{laptop computers}.

	- Improved user interface, including a single point to control
	the entire system.

	- Improved management tools, including remote administration.

	Minimum system requirements, according to Microsoft, are
	{Pentium}-133 {MHz} {CPU}, 64 {MB} {RAM}, 650 {MB} of {hard
	disk} space.  These are for W2K Professional, others require
	more.

	Many {operating systems} compete with Windows 2000, including
	the {Apple} {MacOS}, {Linux}, {FreeBSD}, {OpenBSD}, {NetBSD},
	{Sun} {Solaris}, {IBM} {AIX}, {Hewlett-Packard} {HP-UX}, {SGI}
	{Irix}.  Novell's NDS also provides a service similar to
	Active Directory.

	Windows 2000 will be followed by {Windows XP} Professional and
	{Windows 2002}.

	{Home (http://www.microsoft.com/windows2000/)}.

	{Usenet} newsgroups: {(news:microsoft.public.windows2000)},
	{(news:comp.os.ms-windows)}.

	(2002-01-28)

<World-Wide Web, project> A {open source} {HTTP} server for
	{Unix}, {Windows NT}, and other {platforms}.  Apache was
	developed in early 1995, based on code and ideas found in the
	most popular HTTP server of the time, {NCSA httpd} 1.3.  It
	has since evolved to rival (and probably surpass) almost any
	other {Unix} based HTTP server in terms of functionality, and
	speed.  Since April 1996 Apache has been the most popular HTTP
	server on the {Internet}, in May 1999 it was running on 57% of
	all web servers.

	It features highly configurable error messages, {DBM}-based
	{authentication} {databases}, and {content negotiation}.

	Latest version: 1.3.9, as of 1999-10-27.

	{Home (http://www.apache.org/httpd.html)}.

	{FAQ (http://www.apache.org/docs/misc/FAQ.html)}.

	(1999-10-27)

<architecture> {Data} transferred from a computer system to
	the outside world via some kind of {output device}.

	Opposite: {input}.

	(1997-04-28)

<programming> An unwanted and unintended property of a program
	or piece of hardware, especially one that causes it to
	malfunction.  Antonym of {feature}.  E.g. "There's a bug in
	the editor: it writes things out backward."  The
	identification and removal of bugs in a program is called
	"{debugging}".

	Admiral {Grace Hopper} (an early computing pioneer better
	known for inventing {COBOL}) liked to tell a story in which a
	technician solved a {glitch} in the {Harvard Mark II machine}
	by pulling an actual insect out from between the contacts of
	one of its relays, and she subsequently promulgated {bug} in
	its hackish sense as a joke about the incident (though, as she
	was careful to admit, she was not there when it happened).
	For many years the logbook associated with the incident and
	the actual bug in question (a moth) sat in a display case at
	the Naval Surface Warfare Center (NSWC).  The entire story,
	with a picture of the logbook and the moth taped into it, is
	recorded in the "Annals of the History of Computing", Vol. 3,
	No. 3 (July 1981), pp. 285--286.

	The text of the log entry (from September 9, 1947), reads
	"1545 Relay #70 Panel F (moth) in relay.  First actual case of
	bug being found".  This wording establishes that the term was
	already in use at the time in its current specific sense - and
	Hopper herself reports that the term "bug" was regularly
	applied to problems in radar electronics during WWII.

	Indeed, the use of "bug" to mean an industrial defect was
	already established in Thomas Edison's time, and a more
	specific and rather modern use can be found in an electrical
	handbook from 1896 ("Hawkin's New Catechism of Electricity",
	Theo. Audel & Co.)  which says: "The term "bug" is used to a
	limited extent to designate any fault or trouble in the
	connections or working of electric apparatus."  It further
	notes that the term is "said to have originated in
	{quadruplex} telegraphy and have been transferred to all
	electric apparatus."

	The latter observation may explain a common folk etymology of
	the term; that it came from telephone company usage, in which
	"bugs in a telephone cable" were blamed for noisy lines.
	Though this derivation seems to be mistaken, it may well be a
	distorted memory of a joke first current among *telegraph*
	operators more than a century ago!

	Actually, use of "bug" in the general sense of a disruptive
	event goes back to Shakespeare!  In the first edition of
	Samuel Johnson's dictionary one meaning of "bug" is "A
	frightful object; a walking spectre"; this is traced to
	"bugbear", a Welsh term for a variety of mythological monster
	which (to complete the circle) has recently been reintroduced
	into the popular lexicon through fantasy {role-playing games}.

	In any case, in jargon the word almost never refers to
	insects.  Here is a plausible conversation that never actually
	happened:

	"There is a bug in this ant farm!"

	"What do you mean?  I don't see any ants in it."

	"That's the bug."

	[There has been a widespread myth that the original bug was
	moved to the Smithsonian, and an earlier version of this entry
	so asserted.  A correspondent who thought to check discovered
	that the bug was not there.  While investigating this in late
	1990, your editor discovered that the NSWC still had the bug,
	but had unsuccessfully tried to get the Smithsonian to accept
	it - and that the present curator of their History of
	American Technology Museum didn't know this and agreed that it
	would make a worthwhile exhibit.  It was moved to the
	Smithsonian in mid-1991, but due to space and money
	constraints has not yet been exhibited.  Thus, the process of
	investigating the original-computer-bug bug fixed it in an
	entirely unexpected way, by making the myth true!  - ESR]

	[{Jargon File}]

	(1999-06-29)

1. A program which provides some service to other ({client})
	programs.  The connection between client and server is
	normally by means of {message passing}, often over a
	{network}, and uses some {protocol} to encode the client's
	requests and the server's responses.  The server may run
	continuously (as a {daemon}), waiting for requests to arrive
	or it may be invoked by some higher level daemon which
	controls a number of specific servers ({inetd} on {Unix}).

	There are many servers associated with the {Internet}, such as
	those for {HTTP}, {Network File System}, {Network Information
	Service} (NIS), {Domain Name System} (DNS), {FTP}, {news},
	{finger}, {Network Time Protocol}.  On Unix, a long list can
	be found in /etc/services or in the {NIS} database "services".
	See {client-server}.

	2. A computer which provides some service for other computers
	connected to it via a network.  The most common example is a
	{file server} which has a local disk and services requests
	from remote clients to read and write files on that disk,
	often using {Sun}'s {Network File System} (NFS) {protocol} or
	{Novell Netware} on {PCs}.  Another common example is a {web
	server}.

	[{Jargon File}]

	(2003-12-29)

<text> A set of {glyphs} ({images}) representing the
	{characters} from some particular {character set} in a
	particular size and {typeface}.  The image of each character
	may be encoded either as a {bitmap} (in a {bitmap font}) or by
	a higher-level description in terms of lines and areas (an
	{outline font}).

	There are several different computer representations for
	fonts, the most widely known are {Adobe Systems, Inc.}'s
	{PostScript} font definitions and {Apple}'s {TrueType}.
	{Window systems} can display different fonts on the screen and
	print them.

	[Other types of font?]

	(2001-04-27)