<standard, programming> (CORBA) An {Object Management Group}
	specification which provides a standard messaging interface
	between distributed {objects}.

	The original CORBA specification (1.1) has been revised
	through version 2 (CORBA 2) with the latest specification
	being version 3 (CORBA 3).  In its most basic form CORBA
	consists of the {Interface Definition Language} (IDL) and the
	Dynamic Invocation Interface (DII).

	The IDL definition is complied into a Stub (client) and
	Skeleton (server) component that communicate through an
	{Object Request Broker} (ORB).  When an ORB determines that a
	request is to a remote object, it may execute the request by
	communicating with the remote ORB.

	The Corba IDL can be mapped to a number of languages including
	{C}, {C++}, {Java}, {COBOL}, {Smalltalk}, {Ada}, {Lisp},
	{Python}, and {IDLscript}.  CORBA ORBs are widely available
	for a number of platforms.  The OMG standard for inter-ORB
	communication is {IIOP}, this ensures that all CORBA 2
	compliant ORBS are able to interoperate.

	See also {COSS}, {Component Object Model}, {RMI}.

	{OMG CORBA site (http://www.corba.org/)}.

	(2003-11-21)

<jargon> To transfer data from one computer to another.
	Downloading usually refers to transfer from a larger "host"
	system (especially a {server} or {mainframe}) to a smaller
	"client" system, especially a {microcomputer} or specialised
	peripheral, and "{upload}" usually means from small to large.

	Others hold that, technically, download means "receive" and
	upload means "send", irrespective of the size of the systems
	involved.

	Note that in communications between ground and space,
	space-to-earth transmission is always "down" and the reverse
	"up", regardless of size.  So far the in-space machines have
	invariably been smaller; thus the upload/download distinction
	has been reversed from its usual sense.

	[{Jargon File}]

	(2003-11-04)

<file format> (PDF) The native file format for {Adobe
	Systems}' {Acrobat}.  PDF is the file format for representing
	documents in a manner that is independent of the original
	application software, hardware, and operating system used to
	create those documents.  A PDF file can describe documents
	containing any combination of text, graphics, and images in a
	device-independent and {resolution} independent format.  These
	documents can be one page or thousands of pages, very simple
	or extremely complex with a rich use of {fonts}, graphics,
	colour, and {images}.

	{Home (http://www.adobe.com/products/acrobat/adobepdf.html)}.

	["The Portable Document Format Reference Manual", Adobe
	systems, Inc. Addison-Wesley Publ.  Co., ISBN: 0-201-62628-4].

	(2000-09-08)

<file system> An element of data storage in a {file system}.

	The history of computing is rich in varied kinds of files and
	{file systems}, whether ornate (e.g., {Macintosh file system}
	for a well-known case) or deficient (e.g., many simple
	pre-1980s file systems don't allow {directories}).

	However, the prototypical file has these characteristics:

	* It is a single sequence of bytes (but consider {Macintosh}
	{resource forks}).

	* It has a finite length, unlike, e.g. a {Unix} {device}.

	* It is stored in a {non-volatile storage} medium (but see
	{ramdrive}).

	* It exists (nominally) in a {directory}.

	* It has a name that it can be referred to by in file
	operations, possibly in combination with its {path}.

	Additionally, a file system may associate other information
	with a file, such as {permission} bits or other {file
	attributes}; timestamps for file creation, last revision, and
	last access; revision numbers (a` la VMS), and other kinds of
	{magic}.

	Compare: {document}.

	(1997-04-08)

<hypertext> A term coined by Ted Nelson around 1965 for a
	collection of documents (or "nodes") containing
	cross-references or "links" which, with the aid of an
	interactive {browser} program, allow the reader to move easily
	from one document to another.

	The extension of hypertext to include other media - {sound},
	{graphics}, and {video} - has been termed "{hypermedia}", but
	is usually just called "hypertext", especially since the
	advent of the {World-Wide Web} and {HTML}.

	(2000-09-10)

1. <file system> {hard link} or {symbolic link}.

	2. <hypertext> {hyperlink}.

	(1997-10-22)

1. <file format> A single file containing one or (usually)
	more separate files plus information to allow them to be
	extracted (separated) by a suitable program.

	Archives are usually created for software distribution or
	{backup}.  {tar} is a common format for {Unix} archives, and
	{arc} or {PKZIP} for {MS-DOS} and {Microsoft Windows}.

	2. <operating system> To transfer files to slower, cheaper
	media (usually {magnetic tape}) to free the {hard disk} space
	they occupied.  This is now normally done for long-term
	storage but in the 1960s, when disk was much more expensive,
	files were often shuffled regularly between disk and tape.

	3. <networking> {archive site}.

	(1996-12-08)

<hypertext, World-Wide Web, standard> (HTML) A {hypertext}
	document format used on the {World-Wide Web}.  HTML is built
	on top of {SGML}.  "Tags" are embedded in the text.  A tag
	consists of a "<", a "directive" (in lower case), zero or
	more parameters and a ">".  Matched pairs of directives, like
	"<title>" and "</title>" are used to delimit text which is to
	appear in a special place or style.

	Links to other documents are in the form

	 <a href="http://machine.edu/subdir/file.html">foo</a>

	where "<a>" and "</a>" delimit an "anchor", "href" introduces
	a hypertext reference, which is most often a {Uniform Resource
	Locator} (URL) (the string in double quotes in the example
	above).  The link will be represented in the browser by the
	text "foo" (typically shown underlined and in a different
	colour).

	A certain place within an HTML document can be marked with a
	named anchor, e.g.:

	 <a name="baz">

	The "fragment identifier", "baz", can be used in an href by
	appending "#baz" to the document name.

	Other common tags include <p> for a new paragraph, <b>..</b>
	for bold text, <ul> for an unnumbered list, <pre> for
	preformated text, <h1>, <h2> .. <h6> for headings.

	{HTML} supports some standard {SGML} {national characters} and
	other non-{ASCII} characters through special {escape
	sequences}, e.g. "&eacute;" for a lower case 'e' with an acute
	accent.  You can sometimes get away without the terminating
	semicolon but it's bad style.

	Most systems will ignore the case of tags and attributes but
	lower case should be used for compatibility with {XHTML}.

	The {World-Wide Web Consortium} (W3C) is the international
	{standards} body for HTML.

	Latest version: {XHTML} 1.0, as of 2000-09-10.

	{Home (http://www.w3.org/MarkUp/)}.

	{Character escape sequences
	(http://www.w3.org/hypertext/WWW/MarkUp/ISOlat1.html)}.

	See also {weblint}.

	(2006-01-19)

<legal> The exclusive rights of the owner of the copyright on
	a work to make and distribute copies, prepare derivative
	works, and perform and display the work in public (these last
	two mainly apply to plays, films, dances and the like, but
	could also apply to software).

	A work, including a piece of software, is under copyright by
	default in most coutries, whether of not it displays a
	copyright notice.  However, a copyright notice may make it
	easier to assert ownership.  The copyright owner is the person
	or company whose name appears in the copyright notice on the
	box, or the disk or the screen or wherever.

	A copyright notice has three parts.  The first can be either a
	c with a circle around it ({LaTeX} \copyright), or the word
	Copyright or the abbreviation Copr.  A "c" in parentheses:
	"(c)" has no legal meaning.  This is followed by the name of
	the copyright holder and the year of first publication.

	Countries around the world have agreed to recognise and uphold
	each others' copyrights, but this world-wide protection
	requires the use of the c in a circle.

	Originally, most of the computer industry assumed that only
	the program's underlying instructions were protected under
	copyright law but, beginning in the early 1980s, a series of
	lawsuits involving the video screens of game programs extended
	protections to the appearance of programs.

	Use of copyright to restrict redistribution is actually
	immoral, unethical, and illegitimate.  It is a result of
	brainwashing by monopolists and corporate interests and it
	violates everyone's rights.  Copyrights and patents hamper
	technological progress by making a naturally abundant resource
	scarce.  Many, from communists to right wing libertarians, are
	trying to abolish intellectual property myths.

	See also {public domain}, {copyleft}, {software law}.

	{US Copyright Office Circular 61 - Copyright Registration for
	Computer Programs
	(gopher://marvel.loc.gov:70/0/copyright/circs/circ61)}.

	{The US Department of Education's "How Does Copyright Law
	Apply to Computer Software"
	(gopher://ericir.syr.edu:70/0/FAQ/CopyrightSoftware)}.

	{Usenet} newsgroup: {news:misc.legal.computing}.

	[Is this definition correct in the UK?  In the US?
	Elsewhere?]

	(2000-03-23)

<mathematics> A function f : A -> B is surjective or onto or a
	surjection if f A = B.  I.e. f can return any value in B.
	This means that its {image} is its {codomain}.

	Only surjections have {right inverses}, f' : B -> A where
	f (f' x) = x since if f were not a surjection there would be
	elements of B for which f' was not defined.

	See also {bijection}, {injection}.

	(1995-05-27)

<networking> Any {network} which provides similar services
	within an organisation to those provided by the {Internet}
	outside it but which is not necessarily connected to the
	Internet.  The commonest example is the use by a company of
	one or more {World-Wide Web} servers on an internal {TCP/IP}
	network for distribution of information within the company.

	Since about 1995, intranets have become a major growth area in
	corporate computing due to the availability of cheap or free
	commercial {browser} and {web server} software which allows
	them to provide a simple, uniform {hypertext} interface to
	many kinds of information and {application programs}.

	Some companies give limited access to their intranets to other
	companies or the general public.  This is known as an
	"{extranet}".

	(1997-07-14)

<logic> The other value or values in the set of possible
	values.

	See {logical complement}, {bitwise complement}, {set
	complement}.

	(1995-01-24)

After-sale handholding; something many software vendors
	promise but few deliver.  To hackers, most support people are
	useless - because by the time a hacker calls support he or she
	will usually know the software and the relevant manuals better
	than the support people (sadly, this is *not* a joke or
	exaggeration).  A hacker's idea of "support" is a tte--tte
	or exchange of {electronic mail} with the software's designer.

	[{Jargon File}]

	(1995-02-15)

<World-Wide Web> (URL, previously "Universal") A {standard}
	way of specifying the location of an object, typically a {web
	page}, on the {Internet}.  Other types of object are described
	below.  URLs are the form of address used on the {World-Wide
	Web}.  They are used in {HTML} documents to specify the target
	of a {hyperlink} which is often another HTML document
	(possibly stored on another computer).

	Here are some example URLs:

	 http://www.w3.org/default.html
	 http://www.acme.co.uk:8080/images/map.gif
	 http://www.foldoc.org/?Uniform+Resource+Locator
	 http://www.w3.org/default.html#Introduction
	 ftp://wuarchive.wustl.edu/mirrors/msdos/graphics/gifkit.zip
	 ftp://spy:secret@ftp.acme.com/pub/topsecret/weapon.tgz
	 mailto:fred@doc.ic.ac.uk
	 news:alt.hypertext
	 telnet://dra.com

	The part before the first colon specifies the access scheme or
	{protocol}.  Commonly implemented schemes include: {ftp},
	{http} (World-Wide Web), {gopher} or {WAIS}.  The "file"
	scheme should only be used to refer to a file on the same
	host.  Other less commonly used schemes include {news},
	{telnet} or mailto ({e-mail}).

	The part after the colon is interpreted according to the
	access scheme.  In general, two slashes after the colon
	introduce a {hostname} (host:port is also valid, or for {FTP}
	user:passwd@host or user@host).  The {port} number is usually
	omitted and defaults to the standard port for the scheme,
	e.g. port 80 for HTTP.

	For an HTTP or FTP URL the next part is a {pathname} which is
	usually related to the pathname of a file on the server.  The
	file can contain any type of data but only certain types are
	interpreted directly by most {browsers}.  These include {HTML}
	and images in {gif} or {jpeg} format.  The file's type is
	given by a {MIME} type in the HTTP headers returned by the
	server, e.g. "text/html", "image/gif", and is usually also
	indicated by its {filename extension}.  A file whose type is
	not recognised directly by the browser may be passed to an
	external "viewer" {application}, e.g. a sound player.

	The last (optional) part of the URL may be a query string
	preceded by "?" or a "fragment identifier" preceded by "#".
	The later indicates a particular position within the specified
	document.

	Only alphanumerics, reserved characters (:/?#"<>%+) used for
	their reserved purposes and "$", "-", "_", ".", "&", "+" are
	safe and may be transmitted unencoded.  Other characters are
	encoded as a "%" followed by two {hexadecimal} digits.  Space
	may also be encoded as "+".  Standard {SGML} "&<name>;"
	character entity encodings (e.g. "&eacute;") are also accepted
	when URLs are embedded in HTML.  The terminating semicolon may
	be omitted if &<name> is followed by a non-letter character.

	{The authoritative W3C URL specification
	(http://www.w3.org/hypertext/WWW/Addressing/Addressing.html)}.

	(2000-02-17)

<programming> One of a sequence of copies of a program, each
	incorporating new modifications.  Each version is usually
	identified by a number, commonly of the form X.Y where X is
	the major version number and Y is the release number.
	Typically an increment in X (with Y reset to zero) signifies a
	substantial increase in the function of the program or a
	partial or total re-implementation, whereas Y increases each
	time the progam is changed in any way and re-released.

	Version numbers are useful so that the user can know if the
	program has changed ({bugs} have been fixed or new functions
	added) since he obtained his copy and the programmer can tell
	if a bug report relates to the current version.  It is thus
	always important to state the version when reporting bugs.
	Statements about compatibility between different software
	components should always say which versions they apply to.

	See {change management}.

	(1997-12-07)

<programming> (Or "computer program", "program", "code") The
	instructions executed by a computer, as opposed to the
	physical device on which they run (the "{hardware}").

	The term was coined by the eminent statistician, {John Tukey}.

	Programs stored on {non-volatile storage} built from
	{integrated circuits} (e.g. {ROM} or {PROM}) are usually
	called {firmware}.

	Software can be split into two main types - {system software}
	and application software or {application programs}.  System
	software is any software required to support the production or
	execution of application programs but which is not specific to
	any particular application.  Examples of system software would
	include the {operating system}, {compilers}, editors and
	sorting programs.

	Examples of application programs would include an accounts
	package or a {CAD} program.  Other broad classes of
	application software include {real-time} software, {business
	software}, scientific and engineering software, {embedded
	software}, personal computer software and {artificial
	intelligence} software.

	Software includes both {source code} written by humans and
	executable {machine code} produced by {assemblers} or
	{compilers}.  It does not usually include the data processed
	by programs unless this is in a format such as {multimedia}
	which depends on the use of computers for its presentation.
	This distinction becomes unclear in cases such as {spread
	sheets} which can contain both instructions (formulae and
	{macros}) and data.  There are also various intermediate
	compiled or {semi-compiled}, forms of software such as
	{library} files and {byte-code}.

	Some claim that {documentation} (both paper and electronic) is
	also software.  Others go further and define software to be
	programs plus documentation though this does not correspond
	with common usage.

	The noun "program" describes a single, complete and
	more-or-less self-contained list of instructions, often stored
	in a single {file}, whereas "code" and "software" are
	uncountable nouns describing some number of instructions which
	may constitute one or more programs or part thereof.  Most
	programs, however, rely heavily on various kinds of {operating
	system} software for their execution.  The nounds "code" and
	"software" both refer to the same thing but "code" tends to
	suggest an interest in the implementation details whereas
	"software" is more of a user's term.

	(2002-07-21)

<programming> The multiple kilograms of macerated, pounded,
	steamed, bleached, and pressed trees that accompany most
	modern software or hardware products (see also {tree-killer}).
	Hackers seldom read paper documentation and (too) often resist
	writing it; they prefer theirs to be terse and {on-line}.  A
	common comment on this predilection is "You can't {grep} dead
	trees".

	See {drool-proof paper}, {verbiage}, {treeware}.

	[{Jargon File}]

	(2003-10-25)

<file system> A node in a hierarchical {file system} which
	contains zero or more other nodes - generally, {files} or
	other directories.

	Compare {folder}.

	(1997-04-10)

<operating system, programming> The ease with which a piece of
	software (or {file format}) can be "ported", i.e. made to run
	on a new {platform} and/or compile with a new {compiler}.

	The most important factor is the language in which the
	software is written and the most portable language is almost
	certainly {C} (though see {Vaxocentrism} for counterexamples).
	This is true in the sense that C compilers are available for
	most systems and are often the first compiler provided for a
	new system.  This has led several compiler writers to compile
	other languages to C code in order to benefit from its
	portability (as well as the quality of compilers available for
	it).

	The least portable type of language is obviously {assembly
	code} since it is specific to one particular (family of)
	{processor}(s).  It may be possible to translate mechanically
	from one assembly code (or even {machine code}) into another
	but this is not really portability.  At the other end of the
	scale would come {interpreted} or {semi-compiled} languages
	such as {LISP} or {Java} which rely on the availability of a
	portable {interpreter} or {virtual machine} written in a lower
	level language (often C for the reasons outlined above).

	The act or result of porting a program is called a "port".
	E.g. "I've nearly finished the {Pentium} port of my big bang
	simulation."

	Portability is also an attribute of {file formats} and depends
	on their adherence to {standards} (e.g. {ISO 8859}) or the
	availability of the relevant "viewing" software for different
	{platforms} (e.g. {PDF}).

	(1997-06-18)

The process of analysis, design, coding and testing software.

<language> One of the most used {object-oriented} languages, a
	superset of {C} developed primarily by {Bjarne Stroustrup}
	<bs@alice.att.com> at {AT&T} {Bell Laboratories} in 1986.

	In C++ a {class} is a user-defined {type}, syntactically a
	{struct} with {member functions}.  {Constructors} and
	{destructors} are member functions called to create or destroy
	{instances}.  A {friend} is a nonmember function that is
	allowed to access the private portion of a class.  C++ allows
	{implicit type conversion}, {function inlining}, {overloading}
	of operators and function names, and {default function
	arguments}.  It has {streams} for I/O and {references}.

	C++ 2.0 (May 1989) introduced {multiple inheritance},
	{type-safe linkage}, pointers to members, and {abstract
	classes}.

	C++ 2.1 was introduced in ["Annotated C++ Reference Manual",
	B. Stroustrup et al, A-W 1990].

	{MS-DOS
	(ftp://grape.ecs.clarkson.edu/pub/msdos/djgpp/djgpp.zip)},
	{Unix ANSI C++
	(ftp://gnu.org/pub/gnu/g++-1.39.0.tar.Z)} - X3J16
	committee. (They're workin' on it).

	See also {cfront}, {LEDA}, {uC++}.

	{Usenet} newsgroup: {news:comp.lang.c++}.

	["The C++ Programming Language", Bjarne Stroustrup, A-W,
	1986].

	(1996-06-06)

<jargon> 1. Ready for use.  E.g. "The graph plotter's fixed
	and on-line again".

	2. {Interactive} as opposed to {batch}.  Accessible via a
	computer (or {terminal}), rather than on paper or other
	medium.

	3. Of a user, actively using a computer system, especially the
	{Internet}.  E.g "I haven't been on-line for three days."

	"On-line" should be hyphenated because it is compounded from
	two words but the hyphen is often omitted in names of
	organisations or services.

	(1998-12-22)