<programming> A {component architecture} for the {Java}
	programming language, developed initially by {Sun}, but now
	available from several other vendors.  JavaBeans components
	are called "{beans}".

	JavaBeans allows developers to create reusable software
	components that can then be assembled together using visual
	application builder tools including {Sybase}'s {PowerJ},
	{Borland}'s {JBuilder}, {IBM}'s {Visual Age for Java},
	{SunSoft}'s {Java Workshop} and {Symantec}'s {Visual Cafe}.

	JavaBeans support Introspection (a builder tool can analyze
	how a Bean works), Customisation (developers can customise the
	appearance and behaviour of a Bean), Events (Beans can
	communicate), Properties (developers can customise and program
	with Beans(?)) and Persistence (customised Beans can be stored
	and reused).

	{Home (http://www.javasoft.com/beans/)}.

	(1997-11-20)

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> A {first-in first-out} data structure used to
	sequence multiple demands for a resource such as a {printer},
	{processor} or communications channel.  Objects are added to
	the tail of the queue and taken off the head.

	A typical use of queues in an {operating system} involves a
	user command which places something on a queue, e.g. a file on
	a printer queue or a job on a job queue, and a {background}
	process or "{demon}" which takes things off and processes them
	(e.g. prints or executes them).  Another common use is to pass
	data between an {interrupt handler} and a user process.

	(1995-05-11)

<networking> 1. A lasting connection between a user (or user
	agent) and a {peer}, typically a {server}, usually involving
	the exchange of many packets between the user's computer and
	the server.  A session is typically implemented as a layer in
	a network {protocol} (e.g. {telnet}, {FTP}).

	In the case of protocols where there is no concept of a
	session layer (e.g. {UDP}) or where sessions at the {session
	layer} are generally very short-lived (e.g. {HTTP}), {virtual}
	sessions are implemented by having each exchange between the
	user and the remote host include some form of {cookie} which
	stores state (e.g. a unique session ID, information about the
	user's preferences or authorisation level, etc.).

	See also {login}.

	2. A lasting connection using the {session layer} of a
	networking protocol.

	(1997-08-03)

1. <programming> An {address}, from the point of view of a
	programming language.  A pointer may be typed, with its {type}
	indicating the type of data to which it points.

	The terms "pointer" and "reference" are generally
	interchangable although particular programming languages often
	differentiate these two in subtle ways.  For example, {Perl}
	always calls them references, never pointers.  Conversely, in
	C, "pointer" is used, although "a reference" is often used to
	denote the concept that a pointer implements.

	{Anthony Hoare} once said:

	Pointers are like jumps, leading wildly from one part of the
	data structure to another.  Their introduction into high-level
	languages has been a step backward from which we may never
	recover.

	[C.A.R.Hoare "Hints on Programming Language Design", 1973,
	Prentice-Hall collection of essays and papers by Tony Hoare].

	2. <operating system> (Or "mouse pointer") An {icon}, usually
	a small arrow, that moves on the screen in response to
	movement of a {pointing device}, typically a {mouse}.  The
	pointer shows the user which object on the screen will be
	selected etc. when a mouse button is clicked.

	(1999-07-07)

<language> A {functional programming} language designed by
	R.M. Burstall, D.B. MacQueen and D.T. Sanella at {University
	of Edinburgh} in 1978.  It is a large language supporting
	user-defined {prefix}, {infix} or {distfix} operators.  Hope
	has {polymorphic} typing and allows {overloading} of operators
	which requires explicit type declarations.  Hope has {lazy
	lists} and was the first language to use {call-by-pattern}.

	It has been ported to {Unix}, {Macintosh}, and {IBM PC}.

	See also {Hope+}, {Hope+C}, {Massey Hope}, {Concurrent Massey
	Hope}.

	{(ftp://brolga.cc.uq.oz.au/pub/hope)}.

	[R.M.Burstall, D.B.MacQueen, D.T.Sanella, "HOPE: An
	experimental applicative language", Proc. 1980 Lisp conf.,
	Stanford, CA, p.136-143, Aug 1980].

	["A HOPE Tutorial", R. Bailey, BYTE Aug 1985, pp.235-258].

	["Functional Programming with Hope", R. Bailey, Ellis Horwood
	1990].

	(1992-11-27)