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)

<programming> A computer system or process that requests a
	service of another computer system or process (a "{server}")
	using some kind of {protocol} and accepts the server's
	responses.  A client is part of a {client-server} software
	architecture.

	For example, a {workstation} requesting the contents of a file
	from a {file server} is a client of the file server.

	(1997-10-27)

In {object-oriented programming} sending a message to an
	{object} (to invoke a {method}) is equivalent to calling a
	{procedure} in traditional programming languages, except that
	the actual code executed may only be selected at run time
	depending on the {class} of the object.  Thus, in response to
	the message "drawSelf", the method code invoked would be
	different if the target object were a circle or a square.

	(1995-02-16)

<programming, language, portability> (After the Indonesian island, a
	source of {programming fluid}) A simple, {object-oriented},
	{distributed}, {interpreted}, robust, secure,
	{architecture-neutral}, {portable}, {multithreaded}, dynamic,
	buzzword-compliant, general-purpose programming language
	developed by {Sun Microsystems} in the early 1990's (initially for
	set-top television controllers), and released to the public in 1995.

	Java first became popular by being the earliest portable
	dynamic client-side content for the {World-Wide Web} in the
	form of {platform}-independent Java "applets". In the late
	1990's and into the 2000's it has also become very popular
	on the server side, where an entire set of {APIs} defines the {J2EE}.

	Java is both a set of public specifications (controlled by
	{Sun Microsystems} through the {JCP}) and a series of
	implementations of those specifications.

	Java is syntactially similar to {C++} without user-definable
	{operator overloading}, (though it does have {method}
	overloading), without {multiple inheritance}, and extensive
	automatic {coercions}.  It has automatic {garbage collection}.
	Java extends {C++}'s {object-oriented} facilities with those
	of {Objective C} for {dynamic method resolution}.

	Whereas programs in C++ and similar languages are compiled
	and linked to platform-specific binary executables, Java
	programs are typically compiled to portable {architecture-neutral}
	{bytecode} or ".class" files, which are run using a {Java
	Virtual Machine}.  The JVM is also called an {interpreter},
	though it is more correct to say that it uses {Just-In-Time
	Compilation} to convert the {bytecode} into {native} {machine
	code}, yielding greater efficiency than most interpreted
	languages, rivalling C++ for many long-running, non-GUI
	applications.  The run-time system is typically written in
	{POSIX}-compliant {ANSI C} or {C++}.  Some implementations
	allow Java class files to be translated into {native}
	{machine code} during or after compilation.

	The Java compiler and {linker} both enforce {strong type
	checking} - procedures must be explicitly typed.  Java
	supports the creation of {virus}-free, tamper-free systems
	with {authentication} based on {public-key encryption}.

	Java has an extensive library of routines for all kinds of
	programming tasks, rivalling that of other languages.

	For example, the "java.net} package supports {TCP/IP}
	{protocols} like {HTTP} and {FTP}.  Java applications can
	access objects across the {Internet} via {URLs} almost as easily as
	on the local {file system}. There are also capabilities for
	several types of distributed applications.

	The Java {GUI} libraries provide portable interfaces.  For example,
	there is an abstract Window class and implementations of it
	for {Unix}, {Microsoft Windows} and the {Macintosh}.
	The "java.awt" and "javax.swing" classes can be used either in
	Web-based "Applets" or in client-side or "desktop" applications.

	There are also packages for developing {XML} applications,
	{web services}, {servlets} and other web applications,
	{security}, date and time calculations and I/O formatting,
	database ({JDBC}), and many others.

	Java is not directly related to {JavaScript} despite the name.

	{Home (http://java.sun.com/)}.

	{Usenet} newsgroup: {news:comp.lang.java}.

	(2005-01-21)

<programming> (API, or "application programming interface")
	The interface (calling conventions) by which an {application
	program} accesses {operating system} and other services.  An
	API is defined at {source code} level and provides a level of
	{abstraction} between the application and the {kernel} (or
	other privileged utilities) to ensure the {portability} of the
	code.

	An API can also provide an interface between a {high level
	language} and lower level utilities and services which were
	written without consideration for the {calling conventions}
	supported by compiled languages.  In this case, the API's main
	task may be the translation of parameter lists from one format
	to another and the interpretation of {call-by-value} and
	{call-by-reference} arguments in one or both directions.

	(1995-02-15)

1. The art of debugging a blank sheet of paper (or, in these
	days of on-line editing, the art of debugging an empty file).

	2. A pastime similar to banging one's head against a wall, but
	with fewer opportunities for reward.

	3. The most fun you can have with your clothes on (although
	clothes are not mandatory).

	[{Jargon File}]

	(2003-02-12)

<networking> (LLC) The upper portion of the {data link layer},
	as defined in {IEEE 802.2}.  The LLC sublayer presents a
	uniform interface to the user of the data link service, usually
	the {network layer}.  Beneath the LLC sublayer is the {Media
	Access Control} (MAC) sublayer.

	(1995-02-14)