Basic

application & app

An application (often called "app" for short) is simply a program with a GUI.
Note that it is different from an applet.
boot
Starting up an OS is booting it. If the computer is already running, it is more
often called rebooting.
browser
A browser is a program used to browse the web. Some common browsers
include Netscape, MSIE (Microsoft Internet Explorer), Safari, Lynx,
Mosaic, Amaya, Arena, Chimera, Opera, Cyberdog, HotJava, etc.
bug
A bug is a mistake in the design of something, especially software. A really
severe bug can cause something to crash.
chat
Chatting is like e-mail, only it is done instantaneously and can directly involve
multiple people at once. While e-mail now relies on one more or less
standard protocol, chatting still has a couple competing ones. Of particular
note are IRCand Instant Messenger. One step beyond chatting is
called MUDding.
click
To press a mouse button. When done twice in rapid succession, it is referred
to as a double-click.
cursor
A point of attention on the computer screen, often marked with a flashing line
or block. Text typed into the computer will usually appear at the cursor.
database
A database is a collection of data, typically organized to make common
retrievals easy and efficient. Some common database programs include
Oracle, Sybase, Postgres, Informix, Filemaker, Adabas, etc.
desktop
A desktop system is a computer designed to sit in one position on a desk
somewhere and not move around. Most general purpose computers are
desktop systems. Calling a system a desktop implies nothing about its
platform. The fastest desktop system at any given time is typically either
an Alpha or PowerPC based system, but the SPARC and PA-RISC based
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systems are also often in the running. Industrial strength desktops are
typically called workstations.
directory
Also called "folder", a directory is a collection of files typically created for
organizational purposes. Note that a directory is itself a file, so a directory
can generally contain other directories. It differs in this way from a partition.
disk
A disk is a physical object used for storing data. It will not forget its data
when it loses power. It is always used in conjunction with a disk drive. Some
disks can be removed from their drives, some cannot. Generally it is possible
to write new information to a disk in addition to reading data from it, but this
is not always the case.
drive
A device for storing and/or retrieving data. Some drives (such as disk drives,
zip drives, and tape drives) are typically capable of having new data written
to them, but some others (like CD-ROMs or DVD-ROMs) are not. Some drives
have random access (like disk drives, zip drives, CD-ROMs, and DVD-ROMs),
while others only have sequential access (like tape drives).
e-book
The concept behind an e-book is that it should provide all the functionality of
an ordinary book but in a manner that is (overall) less expensive and more
environmentally friendly. The actual term e-book is somewhat confusingly
used to refer to a variety of things: custom software to play e-book titles,
dedicated hardware to play e-book titles, and the e-book titles themselves.
Individual e-book titles can be free or commercial (but will always be less
expensive than their printed counterparts) and have to be loaded into a
player to be read. Players vary wildly in capability level. Basic ones allow
simple reading and bookmarking; better ones include various features
like hypertext, illustrations, audio, and even limited video. Other optional
features allow the user to mark-up sections of text, leave notes, circle or
diagram things, highlight passages, program or customize settings, and even
use interactive fiction. There are many types of e-book; a couple popular
ones include the Newton book and Palm DOC.
e-mail
E-mail is short for electronic mail. It allows for the transfer of information from
one computer to another, provided that they are hooked up via some sort
of network (often the Internet. E-mail works similarly to FAXing, but its
contents typically get printed out on the other end only on demand, not
immediately and automatically as with FAX. A machine receiving e-mail will
also not reject other incoming mail messages as a busy FAX machine will;
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rather they will instead be queued up to be received after the current batch
has been completed. E-mail is only seven-bit clean, meaning that you should
not expect anything other than ASCII data to go through uncorrupted without
prior conversion via something like uucode or bcode. Some mailers will do
some conversion automatically, but unless you know your mailer is one of
them, you may want to do the encoding manually.
file
A file is a unit of (usually named) information stored on a computer.
firmware
Sort of in-between hardware and software, firmware consists of
modifiable programs embedded in hardware. Firmware updates should be
treated with care since they can literally destroy the underlying hardare if
done improperly. There are also cases where neglecting to apply a firmware
update can destroy the underlying hardware, so user beware.
floppy
An extremely common type of removable disk. Floppies do not hold too much
data, but most computers are capable of reading them. Note though that
there are different competing format used for floppies, so that a floppy
written by one type of computer might not directly work on another. Also
sometimes called "diskette".
format
The manner in which data is stored; its organization. For example, VHS, SVHS,
and Beta are three different formats of video tape. They are not 100%
compatible with each other, but information can be transferred from one to
the other with the proper equipment (but not always without loss; SVHS
contains more information than either of the other two). Computer
information can be stored in literally hundreds of different formats, and can
represent text, sounds, graphics, animations, etc. Computer information can
be exchanged via different computer types provided both computers can
interpret the format used.
function keys
On a computer keyboard, the keys that start with an "F" that are usually (but
not always) found on the top row. They are meant to perform user-defined
tasks.
graphics
Anything visually displayed on a computer that is not text.
hardware
The physical portion of the computer.
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hypertext
A hypertext document is like a text document with the ability to contain
pointers to other regions of (possibly other) hypertext documents.
Internet
The Internet is the world-wide network of computers. There is only one
Internet, and thus it is typically capitalized (although it is sometimes referred
to as "the 'net"). It is different from an intranet.
keyboard
A keyboard on a computer is almost identical to a keyboard on a typewriter.
Computer keyboards will typically have extra keys, however. Some of these
keys (common examples include Control, Alt, and Meta) are meant to be used
in conjunction with other keys just like shift on a regular typewriter. Other
keys (common examples include Insert, Delete, Home, End, Help, function
keys,etc.) are meant to be used independently and often perform editing
tasks. Keyboards on different platforms will often look slightly different and
have somewhat different collections of keys. Some keyboards even have
independent shift lock and caps lock keys. Smaller keyboards with only mathrelated keys are typically called "keypads".
language
Computer programs can be written in a variety of different languages.
Different languages are optimized for different tasks. Common languages
include Java, C, C++, ForTran, Pascal, Lisp, and BASIC. Some people classify
languages into two categories, higher-level and lower-level. These people
would consider assembly language and machine language lower-level
languages and all other languages higher-level. In general, higher-level
languages can be eitherinterpreted or compiled; many languages allow both,
but some are restricted to one or the other. Many people do not consider
machine language and assembly language at all when talking about
programming languages.
laptop
A laptop is any computer designed to do pretty much anything
a desktop system can do but run for a short time (usually two to five hours)
on batteries. They are designed to be carried around but are not particularly
convenient to carry around. They are significantly more expensive than
desktop systems and have far worse battery life than PDAs. Calling a system
a laptop implies nothing about its platform. By far the fastest laptops are
the PowerPC based Macintoshes.
memory
Computer memory is used to temporarily store data. In reality, computer
memory is only capable of remembering sequences of zeros and ones, but by
4

utilizing the binary number system it is possible to produce arbitrary rational

numbers and through clever formatting all manner of representations of
pictures, sounds, and animations. The most common types of memory
are RAM, ROM, and flash.
MHz & megahertz
One megahertz is equivalent to 1000 kilohertz, or 1,000,000 hertz. The clock
speed of the main processor of many computers is measured in MHz, and is
sometimes (quite misleadingly) used to represent the overall speed of a
computer. In fact, a computer's speed is based upon many factors, and since
MHz only reveals how many clock cycles the main processor has per second
(saying nothing about how much is actually accomplished per cycle), it can
really only accurately be used to gauge two computers with the same
generation and family of processor plus similar configurations of memory, coprocessors, and other peripheral hardware.
modem
A modem allows two computers to communicate over ordinary phone lines. It
derives its name from modulate /demodulate, the process by which it
converts digital computer data back and forth for use with an analog phone
line.
monitor
The screen for viewing computer information is called a monitor.
mouse
In computer parlance a mouse can be both the physical object moved around
to control a pointer on the screen, and the pointer itself. Unlike the animal,
the proper plural of computer mouse is "mouses".
multimedia
This originally indicated a capability to work with and integrate various types
of things including audio, still graphics, and especially video. Now it is more
of a marketing term and has little real meaning. Historically the Amiga was
the first multimedia machine. Today in addition
to AmigaOS, IRIX and Solaris are popular choices for high-end multimedia
work.
NC
The term network computer refers to any (usually desktop) computer system
that is designed to work as part of anetwork rather than as a stand-alone
machine. This saves money on hardware, software, and maintenance by
taking advantage of facilities already available on the network. The term
"Internet appliance" is often used interchangeably with NC.
network
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A network (as applied to computers) typically means a group of computers

working together. It can also refer to the physical wire etc. connecting the
computers.
notebook
A notebook is a small laptop with similar price, performance, and battery life.
organizer
An organizer is a tiny computer used primarily to store names, addresses,
phone numbers, and date book information. They usually have some ability
to exchange information with desktop systems. They boast even better
battery life thanPDAs but are far less capable. They are extremely
inexpensive but are typically incapable of running any special
purpose applications and are thus of limited use.
OS
The operating system is the program that manages a computer's resources.
Common OSes include Windows
'95,MacOS, Linux, Solaris, AmigaOS, AIX, Windows NT, etc.
PC
The term personal computer properly refers to any desktop, laptop,
or notebook computer system. Its use is inconsistent, though, and some use
it to specifically refer to x86 based systems running MS-DOS, MSWindows, GEOS, or OS/2. This latter use is similar to what is meant by
a WinTel system.
PDA
A personal digital assistant is a small battery-powered computer intended to
be carried around by the user rather than left on a desk. This means that
the processor used ought to be power-efficient as well as fast, and
the OS ought to be optimized for hand-held use. PDAs typically have an
instant-on feature (they would be useless without it) and most are grayscale
rather than color because of battery life issues. Most have a pen interface
and come with a detachable stylus. None use mouses. All have some ability
to exchange data with desktop systems. In terms of raw capabilities, a PDA is
more capable than an organizer and less capable than a laptop (although
some high-end PDAs beat out some low-end laptops). By far the most popular
PDA is the Pilot, but other common types
include Newtons, Psions, Zauri, Zoomers, and Windows CE hand-helds. By far
the fastest current PDA is the Newton (based around
a StrongARM RISCprocessor). Other PDAs are optimized for other tasks; few
computers are as personal as PDAs and care must be taken in their
purchase. Feneric's PDA / Handheld Comparison Page is perhaps the most
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detailed comparison of PDAs and handheld computers to be found anywhere

on the web.
platform
Roughly speaking, a platform represents a computer's family. It is defined by
both the processor type on the hardwareside and the OS type on
the software side. Computers belonging to different platforms cannot
typically run each other'sprograms (unless the programs are written in
a language like Java).
portable
If something is portable it can be easily moved from one type of computer to
another. The verb "to port" indicates the moving itself.
printer
A printer is a piece of hardware that will print computer information onto
paper.
processor
The processor (also called central processing unit, or CPU) is the part of the
computer that actually works with the data and runs the programs. There are
two main processor types in common usage today: CISC and RISC. Some
computers have more than one processor and are thus called
"multiprocessor". This is distinct from multitasking. Advertisers often
use megahertz numbers as a means of showing a processor's speed. This is
often extremely misleading; megahertz numbers are more or less
meaningless when compared across different types of processors.
program
A program is a series of instructions for a computer, telling it what to do or
how to behave. The terms "application" and "app" mean almost the same
thing (albeit applications generally have GUIs). It is however different from
an applet. Program is also the verb that means to create a program, and a
programmer is one who programs.
run
Running a program is how it is made to do something. The term "execute"
means the same thing.
software
The non-physical portion of the computer; the part that exists only as data;
the programs. Another term meaning much the same is "code".
spreadsheet
An program used to perform various calculations. It is especially popular for
financial applications. Some common spreadsheets include Lotus 123,
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Excel, OpenOffice Spreadsheet, Octave, Gnumeric, AppleWorks

Spreadsheet, Oleo, and GeoCalc.
user
The operator of a computer.
word processor
A program designed to help with the production of textual documents, like
letters and memos. Heavier duty work can be done with a desktop publisher.
Some common word processors include MS-Word, OpenOffice Write,
WordPerfect,AbiWord, AppleWorks Write, and GeoWrite.
www
The World-Wide-Web refers more or less to all the publically accessable
documents on the Internet. It is used quite loosely, and sometimes indicates
only HTML files and sometimes FTP and Gopher files, too. It is also sometimes
just referred to as "the web".

Reference
65xx
The 65xx series of processors includes the 6502, 65C02, 6510, 8502, 65C816,
65C816S, etc. It is a CISC design and is not being used in too many new
stand-alone computer systems, but is still being used in embedded systems,
game systems (such as the Super NES), and processor enhancement add-ons
for older systems. It was originally designed by MOS Technologies, but is now
produced by The Western Design Center, Inc. It was the primary processor for
many extremely popular systems no longer being produced, including the
Commodore 64, the Commodore 128, and all the Apple ][ series machines.
68xx
The 68xx series of processors includes the 6800, 6805, 6809, 68000, 68020,
68030, 68040, 68060, etc. It is a CISCdesign and is not being used in too
many new stand-alone computer systems, but is still being used heavily
in embeddedsystems. It was originally designed by Motorola and was the
primary processor for older generations of many current machines,
including Macintoshes, Amigas, Sun workstations, HP workstations, etc. and
the primary processor for many systems no longer being produced, such as
the TRS-80. The PowerPC was designed in part to be its replacement.
a11y
Commonly used to abbreviate the word "accessibility". There are eleven
letters between the "a" and the "y".
ADA
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An object-oriented language at one point popular for military and some

academic software. Lately C++ and Java have been getting more attention.
AI
Artificial intelligence is the concept of making computers do tasks once
considered to require thinking. AI makes computers play chess, recognize
handwriting and speech, helps suggest prescriptions to doctors for patients
based on imput symptoms, and many other tasks, both mundane and not.
AIX
The industrial strength OS designed by IBM to run on PowerPC and x86 based
machines. It is a variant of UNIX and is meant to provide more power
than OS/2.
AJaX
AJaX is a little like DHTML, but it adds asynchronous communication between
the browser and Web site via eitherXML or JSON to achieve performance that
often rivals desktop applications.
Alpha
An Alpha is a RISC processor invented by Digital and currently produced by
Digital/Compaq and Samsung. A few different OSes run on Alpha based
machines including Digital UNIX, Windows NT, Linux, NetBSD, and AmigaOS.
Historically, at any given time, the fastest processor in the world has usually
been either an Alpha or a PowerPC (with sometimes SPARCs and PARISCs making the list), but Compaq has recently announced that there will be
no further development of this superb processor instead banking on the
release of the somewhat suspect Merced.
AltiVec
AltiVec (also called the "Velocity Engine") is a special extension built into
some PowerPC CPUs to provide better performance for certain operations,
most notably graphics and sound. It is similar to MMX on the x86 CPUs. Like
MMX, it requires special software for full performance benefits to be realized.
Amiga
A platform originally created and only produced by Commodore, but now
owned by Gateway 2000 and produced by it and a few smaller companies. It
was historically the first multimedia machine and gave the world of
computing many innovations. It is now primarily used for audio / video
applications; in fact, a decent Amiga system is less expensive than a less
capable video editing system. Many music videos were created on Amigas,
and a few television series and movies had their special effects generated on
Amigas. Also, Amigas can be readily synchronized with video cameras, so
typically when a computer screen appears on television or in a movie and it is
not flickering wildly, it is probably an Amiga in disguise. Furthermore, many
9

coin-operated arcade games are really Amigas packaged in stand-up boxes.

Amigas have AmigaOS for their OS. New Amigas have either a PowerPC or
an Alpha for their main processor and a68xx processor dedicated
to graphics manipulation. Older (and low end) Amigas do everything with just
a 68xx processor.
AmigaOS
The OS used by Amigas. AmigaOS combines the functionality of an OS and
a window manager and is fullymultitasking. AmigaOS boasts a pretty good
selection of games (many arcade games are in fact written on Amigas) but
has limited driver support. AmigaOS will run on 68xx, Alpha,
and PowerPC based machines.
Apple ][
The Apple ][ computer sold millions of units and is generally considered to
have been the first home computer with a 1977 release date. It is based on
the 65xx family of processors. The earlier Apple I was only available as a
build-it-yourself kit.
AppleScript
A scripting language for Mac OS computers.
applet
An applet differs from an application in that is not meant to be run standalone but rather with the assistance of another program, usually a browser.
AppleTalk
AppleTalk is a protocol for computer networks. It is arguably inferior to TCP/IP.
Aqua
The default window manager for Mac OS X.
Archie
Archie is a system for searching through FTP archives for particular files. It
tends not to be used too much anymore as more general modern search
engines are significantly more capable.
ARM
An ARM is a RISC processor invented by Advanced RISC Machines, currently
owned by Intel, and currently produced by both the above and
Digital/Compaq. ARMs are different from most other processors in that they
were not designed to maximize speed but rather to maximize speed per
power consumed. Thus ARMs find most of their use on hand-held machines
and PDAs. A few different OSes run on ARM based machines including Newton
OS, JavaOS, and (soon)Windows CE and Linux. The StrongARM is a more
10

recent design of the original ARM, and it is both faster and more power
efficient than the original.
ASCII
The ASCII character set is the most popular one in common use. People will
often refer to a bare text file without complicated embedded format
instructions as an ASCII file, and such files can usually be transferred from
one computer system to another with relative ease. Unfortunately there are a
few minor variations of it that pop up here and there, and if you receive a text
file that seems subtly messed up with punctuation marks altered or upper
and lower case reversed, you are probably encountering one of the ASCII
variants. It is usually fairly straightforward to translate from one ASCII variant
to another, though. The ASCII character set is seven bit while pure binary is
usually eight bit, so transferring a binary file through ASCII channels will
result in corruption and loss of data. Note also that the ASCII character set is
a subset of the Unicode character set.
ASK
A protocol for an infrared communications port on a device. It predates
the IrDA compliant infrared communications protocol and is not compatible
with it. Many devices with infrared communications support both, but some
only support one or the other.
assembly language
Assembly language is essentially machine language that has had some of the
numbers replaced by somewhat easier to remember mnemonics in an
attempt to make it more human-readable. The program that converts
assembly language to machine language is called an assembler. While
assembly language predates FORTRAN, it is not typically what people think of
when they discuss computer languages.
Atom
Atom is an intended replacement for RSS and like it is used for syndicating a
web site's content. It is currently not nearly as popular or well-supported by
software applications, however.
authoring system
Any GUIs method of designing new software can be called an authoring
system. Any computer language name with the word "visual" in front of it is
probably a version of that language built with some authoring system
capabilities. It appears that the first serious effort to produce a commercial
quality authoring system took place in the mid eighties for the Amiga.
AWK
AWK is an interpreted language developed in 1977 by Aho, Weinberger, &
Kernighan. It gets its name from its creators' initials. It is not particularly fast,
11

but it was designed for creating small throwaway programs rather than fullblown applications -- it is designed to make the writing of the program fast,
not the program itself. It is quite portablewith versions existing for
numerous platforms, including a free GNU version. Plus, virtually every
version of UNIX in the world comes with AWK built-in.
BASIC
The Beginners' All-purpose Symbolic Instruction Code is a
computer language developed by Kemeny & Kurtz in 1964. Although it is
traditionally interpreted, compilers exist for many platforms. While the
interpreted form is typically fairly slow, the compiled form is often quite fast,
usually faster than Pascal. The biggest problem with BASIC is portability;
versions for different machines are often completely unlike each
other; Amiga BASIC at first glance looks more like Pascal, for example.
Portability problems actually go beyond even the cross platform level; in fact,
most machines have multiple versions of incompatible BASICs available for
use. The most popular version of BASIC today is called Visual BASIC. Like all
BASICs it has portability issues, but it has some of the advantages of
an authoring system so it is relatively easy to use.
baud
A measure of communications speed, used typically for modems indicating
how many bits per second can be transmitted.
BBS
A bulletin board system is a computer that can be directly connected to
via modem and provides various services like e-mail, chatting, newsgroups,
and file downloading. BBSs have waned in popularity as more and more
people are instead connecting to the Internet, but they are still used for
product support and local area access. Most current BBSs provide some sort
of gateway connection to the Internet.
bcode
Identical in intent to uucode, bcode is slightly more efficient and
more portable across different computer types. It is the preferred method
used by MIME.
BeOS
A lightweight OS available for both PowerPC and x86 based machines. It is
often referred to simply as "Be".
beta
A beta version of something is not yet ready for prime time but still possibly
useful to related developers and other interested parties. Expect
beta software to crash more than properly released software does.
Traditionally beta versions (of commercial software) are distributed only to
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selected testers who are often then given a discount on the proper version
after its release in exchange for their testing work. Beta versions of noncommercial software are more often freely available to anyone who has an
interest.
binary
There are two meanings for binary in common computer usage. The first is
the name of the number system in which there are only zeros and ones. This
is important to computers because all computer data is ultimately a series of
zeros and ones, and thus can be represented by binary numbers. The second
is an offshoot of the first; data that is not meant to be intepreted through a
common character set (like ASCII) is typically referred to as binary data. Pure
binary data is typically eight bit data, and transferring a binary file through
ASCII channels without prior modification will result in corruption and loss of
data. Binary data can be turned into ASCII data via uucoding or bcoding.
bit
A bit can either be on or off; one or zero. All computer data can ultimately be
reduced to a series of bits. The term is also used as a (very rough) measure
of sound quality, color quality, and even procesor capability by considering
the fact that series of bits can represent binary numbers. For example
(without getting too technical), an eight bit image can contain at most 256
distinct colors while a sixteen bit image can contain at most 65,536 distinct
colors.
bitmap
A bitmap is a simplistic representation of an image on a computer, simply
indicating whether or not pixels are on or off, and sometimes indicating their
color. Often fonts are represented as bitmaps. The term "pixmap" is
sometimes used similarly; typically when a distinction is made, pixmap refers
to color images and bitmap refers to monochrome images.
blog
Short for web log, a blog (or weblog, or less commonly, 'blog) is a web site
containing periodic (usually frequent) posts. Blogs are usually syndicated via
either some type of RSS or Atom and often supports TrackBacks. It is not
uncommon for blogs to function much like newspaper columns. A blogger is
someone who writes for and maintains a blog.
boolean
Boolean algebra is the mathematics of base two numbers. Since base two
numbers have only two values, zero and one, there is a good analogy
between base two numbers and the logical values "true" & "false". In
common usage, booleans are therefore considered to be simple logical values
like true & false and the operations that relate them, most typically "and",
13

"or" and "not". Since everyone has a basic understanding of the concepts of
true & false and basic conjunctions, everyone also has a basic understanding
of boolean concepts -- they just may not realize it.
byte
A byte is a grouping of bits. It is typically eight bits, but there are those who
use non-standard byte sizes. Bytes are usually measured in large groups, and
the term "kilobyte" (often abbreviated as K) means one-thousand twenty-four
(1024) bytes; the term "megabyte" (often abbreviated as M) means onethousand twenty-four (1024) K; the term gigabyte (often abbreviated as G)
means one-thousand twenty-four (1024) M; and the term "terabyte" (often
abbreviated as T) means one-thousand twenty-four (1024) G. Memory is
typically measured in kilobytes or megabytes, and disk space is typically
measured in megabytes or gigabytes. Note that the multipliers here are 1024
instead of the more common 1000 as would be used in the metric system.
This is to make it easier to work with the binary number system. Note also
that some hardware manufacturers will use the smaller 1000 multiplier on M
& G quantities to make their disk drives seem larger than they really are;
buyer beware.
bytecode
Sometimes computer languages that are said to be
either interpreted or compiled are in fact neither and are more accurately
said to be somewhere in between. Such languages are compiled into
bytecode which is then interpreted on the target system. Bytecode tends to
be binary but will work on any machine with the appropriate runtime
environment(or virtual machine) for it.
C
C is one of the most popular computer languages in the world, and quite
possibly the most popular. It is a compiledlangauge widely supported on
many platforms. It tends to be more portable than FORTRAN but less portable
than Java; it has been standardized by ANSI as "ANSI C" -- older versions are
called either "K&R C" or "Kernighan and Ritchie C" (in honor of C's creators),
or sometimes just "classic C". Fast and simple, it can be applied to all manner
of general purpose tasks. C compilers are made by several companies, but
the free GNU version (gcc) is still considered one of the best. Newer Clike object-oriented languages include both Java and C++.
C#
C# is a compiled object-oriented language based heavily on C++ with
some Java features.
C++
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C++ is a compiled object-oriented language. Based heavily on C, C++ is

nearly as fast and can often be thought of as being just C with added
features. It is currently probably the second most popular object-oriented
language, but it has the drawback of being fairly complex -- the much simpler
but somewhat slower Java is probably the most popular object-oriented
language. Note that C++ was developed independently of the somewhat
similar Objective-C; it is however related to Objective-C++.
C64/128
The Commodore 64 computer to this day holds the record for being the most
successful model of computer ever made with even the lowest estimates
being in the tens of millions. Its big brother, the Commodore 128, was not
quite as popular but still sold several million units. Both units sported ROMbased BASIC and used it as a default "OS". The C128 also came with CP/M (it
was a not-often-exercized option on the C64). In their later days they were
also packaged with GEOS. Both are based on 65xx family processors. They
are still in use today and boast a friendly and surprisingly
active user community. There is even a current effort to port Linux to the C64
and C128 machines.
CDE
The common desktop environment is a popular commercial window
manager (and much more -- as its name touts, it is more of a desktop
environment) that runs under X-Windows. Free work-alike versions are also
available.
chain
Some computer devices support chaining, the ability to string multiple
devices in a sequence plugged into just one computer port. Often, but not
always, such a chain will require some sort of terminator to mark the end. For
an example, a SCSI scanner may be plugged into a SCSI CD-ROM drive that is
plugged into a SCSI hard drive that is in turn plugged into the main computer.
For all these components to work properly, the scanner would also have to
have a proper terminator in use. Device chaining has been around a long
time, and it is interesting to note that C64/128 serialdevices supported it from
the very beginning. Today the most common low-cost chainable devices in
use support USBwhile the fastest low-cost chainable devices in use
support FireWire.
character set
Since in reality all a computer can store are series of zeros and ones,
representing common things like text takes a little work. The solution is to
view the series of zeros and ones instead as a sequence of bytes, and map
each one to a particular letter, number, or symbol. The full mapping is called
a character set. The most popular character set is commonly referred to
15

as ASCII. The second most popular character set these days is Unicode (and it
will probably eventually surpass ASCII). Other fairly common character sets
include EBCDIC and PETSCII. They are generally quite different from one
another; programs exist to convert between them on most platforms, though.
Usually EBCDIC is only found on really old machines.
CISC
Complex instruction set computing is one of the two main types of processor
design in use today. It is slowly losing popularity to RISC designs; currently all
the fastest processors in the world are RISC. The most popular current CISC
processor is the x86, but there are also still some 68xx, 65xx, and Z80s in
use.
CLI
A command-line interface is a text-based means of communicating with
a program, especially an OS. This is the sort of interface used by MS-DOS, or
a UNIX shell window.
COBOL
The Common Business Oriented Language is a language developed back in
1959 and still used by some businesses. While it is relatively portable, it is
still disliked by many professional programmers simply because
COBOL programstend to be physically longer than equivalent programs
written in almost any other language in common use.
compiled
If a program is compiled, its original human-readable source has been
converted into a form more easily used by a computer prior to it being run.
Such programs will generally run more quickly than interpreted programs,
because time was pre-spent in the compilation phase. A program that
compiles other programs is called a compiler.
compression
It is often possible to remove redundant information or capitalize on patterns
in data to make a file smaller. Usually when a file has been compressed, it
cannot be used until it is uncompressed. Image files are common exceptions,
though, as many popular image file formats have compression built-in.
cookie
A cookie is a small file that a web page on another machine writes to your
personal machine's disk to store various bits of information. Many people
strongly detest cookies and the whole idea of them, and most browsers allow
the reception of cookies to be disabled or at least selectively disabled, but it
should be noted that both Netscape and MSIE have silent cookie reception
enabled by default. Sites that maintain shopping carts or remember a
reader's last position have legitimate uses for cookies. Sites without such
16

functionality that still spew cookies with distant (or worse, non-existent)
expiration dates should perhaps be treated with a little caution.
CP/M
An early DOS for desktops, CP/M runs on both Z80 and the x86 based
machines. CP/M provides only a CLI and there really is not any standard way
to get a window manager to run on top of it. It is fairly complex and tricky to
use. In spite of all this, CP/M was once the most popular DOS and is still in
use today.
crash
If a bug in a program is severe enough, it can cause that program to crash, or
to become inoperable without being restarted. On machines that are
not multitasking, the entire machine will crash and have to be rebooted. On
machines that are only partially multitasking the entire machine will
sometimes crash and have to be rebooted. On machines that are fully
multitasking, the machine should never crash and require a reboot.
Cray
A Cray is a high-end computer used for research and frequently heavyduty graphics applications. Modern Crays typically have Solaris for
their OS and sport sixty-four RISC processors; older ones had various other
configurations. Current top-of-the-line Crays can have over 2000 processors.
crippleware
Crippleware is a variant of shareware that will either self-destruct after its
trial period or has built-in limitations to its functionality that get removed
after its purchase.
CSS
Cascading style sheets are used in conjunction with HTML and XHTML to
define the layout of web pages. While CSSis how current web pages declare
how they should be displayed, it tends not to be supported well (if at all) by
ancientbrowsers. XSL performs this same function more generally.
desktop publisher
A program for creating newspapers, magazines, books, etc. Some common
desktop publishing programs include FrameMaker, PageMaker, InDesign, and
GeoPublish.
DHTML
Dynamic HTML is simply the combined use of
both CSS and JavaScript together in the same document; a more extreme
form is called AJaX. Note that DHTML is quite different from the similarly
named DTML.
17

dict
A protocol used for looking up definitions across a network (in particular
the Internet).
digital camera
A digital camera looks and behaves like a regular camera, except instead of
using film, it stores the image it sees inmemory as a file for later transfer to a
computer. Many digital cameras offer additional storage besides their own
internal memory; a few sport some sort of disk but the majority utilize some
sort of flash card. Digital cameras currently lack the resolution and color
palette of real cameras, but are usually much more convenient for computer
applications. Another related device is called a scanner.
DIMM
A physical component used to add RAM to a computer. Similar to, but
incompatible with, SIMMs.
DNS
Domain name service is the means by which a name
(like www.saugus.net or ftp.saugus.net) gets converted into a
realInternet address that points to a particular machine.
DOS
A disk operating system manages disks and other system resources. Sort of
a subset of OSes, sort of an archaic term for the same. MS-DOS is the most
popular program currently calling itself a DOS. CP/M was the most popular
prior to MS-DOS.
DoS
In a denial of service attack, many individual (usually compromised)
computers are used to try and simultaneously access the same public
resource with the intent of overburdening it so that it will not be able to
adequately serve its normal users.
download
To download a file is to copy it from a remote computer to your own. The
opposite is upload.
DR-DOS
The DOS currently produced by Caldera (originally produced by Design
Research as a successor to CP/M) designed to work like MS-DOS. While similar
to CP/M in many ways, it utilizes simpler commands. It provides only a CLI,
but either Windows 3.1 or GEOS may be run on top of it to provide a GUI. It
only runs on x86 based machines.
driver
18

A driver is a piece of software that works with the OS to control a particular

piece of hardware, like a printer or ascanner or a mouse or whatever.
DRM
Depending upon whom you ask, DRM can stand for either Digital Rights
Management or Digital Restrictions Management. In either case, DRM is used
to place restrictions upon the usage of digital media ranging from software to
music to video.
DTML
The Document Template Mark-up Language is a subset of SGML and a
superset of HTML used for creating documents that dynamically adapt to
external conditions using its own custom tags and a little bit of Python. Note
that it is quite different from the similarly named DHTML.
EDBIC
The EDBIC character set is similar to (but less popular than)
the ASCII character set in concept, but is significantly different in layout. It
tends to be found only on old machines..
emacs
Emacs is both one of the most powerful and one of the most popular text
editing programs in existence. Versions can be found for most platforms, and
in fact multiple companies make versions, so for a given platform there might
even be a choice. There is even a free GNU version available. The drawback
with emacs is that it is not in the least bitlightweight. In fact, it goes so far in
the other direction that even its advocates will occasionally joke about it. It is
however extremely capable. Almost anything that one would need to relating
to text can be done with emacs and is probably built-in. Even if one manages
to find something that emacs was not built to do, emacs has a builtin Lispinterpreter capable of not only extending its text editing capabilities,
but even of being used as a scripting language in its own right.
embedded
An embedded system is a computer that lives inside another device and acts
as a component of that device. For example, current cars have an embedded
computer under the hood that helps regulate much of their day to day
operation.
An embedded file is a file that lives inside another and acts as a portion of
that file. This is frequently seen with HTMLfiles having embedded audio files;
audio files often embedded in HTML
include AU files, MIDI files, SID files, WAVfiles, AIFF files, and MOD files.
Most browsers will ignore these files unless an appropriate plug-in is present.
emulator
19

An emulator is a program that allows one computer platform to mimic

another for the purposes of running its software. Typically (but not always)
running a program through an emulator will not be quite as pleasent an
experience as running it on the real system.
endian
A processor will be either "big endian" or "little endian" based upon the
manner in which it encodes multiple bytevalues. There is no difference in
performance between the two encoding methods, but it is one of the sources
of difficulty when reading binary data on different platforms.
environment
An environment (sometimes also called a runtime environment) is a
collection of external variable items or parameters that a program can access
when run. Information about the computer's hardware and the user can often
be found in the environment.
EPOC
EPOC is a lightweight OS. It is most commonly found on the Psion PDA.
extension
Filename extensions originate back in the days of CP/M and basically allow a
very rough grouping of different filetypes by putting a tag at the end of the
name. To further complicate matters, the tag is sometimes separated by the
name proper by a period "." and sometimes by a tab. While extensions are
semi-enforced on CP/M, MS-DOS, and MS-Windows, they have no real
meaning aside from convention on other platforms and are only optional.
FAQ
A frequently asked questions file attempts to provide answers for all
commonly asked questions related to a given topic.
FireWire
An incredibly fast type of serial port that offers many of the best features
of SCSI at a lower price. Faster than most types of parallel port, a single
FireWire port is capable of chaining many devices without the need of
a terminator. FireWire is similar in many respects to USB but is significantly
faster and somewhat more expensive. It is heavily used for connecting
audio/video devices to computers, but is also used for connecting storage
devices like drives and other assorted devices like printers and scanners.
fixed width
As applied to a font, fixed width means that every character takes up the
same amount of space. That is, an "i" will be just as wide as an "m" with
empty space being used for padding. The opposite is variable width. The
most common fixed width font is Courier.
20

flash
Flash memory is similar to RAM. It has one significant advantage: it does not
lose its contents when power is lost; it has two main disadvantages: it is
slower, and it eventually wears out. Flash memory is frequently found
in PCMCIA cards.
font
In a simplistic sense, a font can be thought of as the physical description of
a character set. While the character set will define what sets of bits map to
what letters, numbers, and other symbols, the font will define what each
letter, number, and other symbol looks like. Fonts can be either fixed
width or variable width and independently, either bitmapped orvectored. The
size of the large characters in a font is typically measured in points.
Forth
A language developed in 1970 by Moore. Forth is fairly portable and has
versions on many different platforms. While it is no longer an very popular
language, many of its ideas and concepts have been carried into other
computer programs. In particular, some programs for doing heavy-duty
mathematical and engineering work use Forth-like interfaces.
FORTRAN
FORTRAN stands for formula translation and is the oldest
computer language in the world. It is typically compiled and is quite fast. Its
primary drawbacks are portability and ease-of-use -- often different FORTRAN
compilers on differentplatforms behave quite differently in spite of
standardization efforts in 1966 (FORTRAN 66 or FORTRAN IV), 1978 (FORTRAN
77), and 1991 (FORTRAN 90). Today languages like C and Java are more
popular, but FORTRAN is still heavily used in military software. It is somewhat
amusing to note that when FORTRAN was first released back in 1958 its
advocates thought that it would mean the end of software bugs. In truth of
course by making the creation of more complex software practical, computer
languages have merely created new types of software bugs.
FreeBSD
A free variant of Berkeley UNIX available for Alpha and x86 based machines.
It is not as popular as Linux.
freeware
Freeware is software that is available for free with no strings attached. The
quality is often superb as the authors are also generally users.
FTP
The file transfer protocol is one of the most commonly used methods of
copying files across the Internet. It has its origins on UNIX machines, but has
been adapted to almost every type of computer in existence and is built into
21

manybrowsers. Most FTP programs have two modes of operation, ASCII,

and binary. Transmitting an ASCII file via the ASCII mode of operation is more
efficient and cleaner. Transmitting a binary file via the ASCII mode of
operation will result in a broken binary file. Thus the FTP programs that do not
support both modes of operation will typically only do the binary mode, as
binary transfers are capable of transferring both kinds of data without
corruption.
gateway
A gateway connects otherwise separate computer networks.
GEOS
The graphic environment operating system is a lightweight OS with a GUI. It
runs on several different processors, including the 65xx (different versions for
different machines -- there are versions for the C64, the C128, and the
Apple ][, each utilizing the relevant custom chip sets), the x86 (although the
x86 version is made to run on top of MS-DOS (orPC-DOS or DR-DOS) and is
not strictly a full OS or a window manager, rather it is somewhat in between,
likeWindows 3.1) and numerous different PDAs, embedded devices, and
hand-held machines. It was originally designed by Berkeley Softworks (no real
relation to the Berkeley of UNIX fame) but is currently in a more interesting
state: the company GeoWorks develops and promotes development of GEOS
for hand-held devices, PDAs, & and embedded devices and owns (but has
ceased further development on) the x86 version. The other versions are
owned (and possibly still being developed) by the company CMD.
GHz & gigahertz
One gigahertz is equivalent to 1000 megahertz, or 1,000,000,000 hertz.
Glulx
A virtual machine optimized for running interactive fiction, interactive
tutorials, and other interactive things of a primarily textual nature. Glulx has
been ported to several platforms, and in in many ways an upgrade to the Zmachine.
GNOME
The GNU network object model environment is a popular free window
manager (and much more -- as its name touts, it is more of a desktop
environment) that runs under X-Windows. It is a part of the GNU project.
GNU
GNU stands for GNU's not UNIX and is thus a recursive acronym (and unlike
the animal name, the "G" here is pronounced). At any rate, the GNU project is
an effort by the Free Software Foundation (FSF) to make all of the
traditional UNIX utilities free for whoever wants them. The Free Software
Foundation programmers know their stuff, and the quality of the
22

GNU software is on par with the best produced commercially, and often
better. All of the GNU software can be downloaded for free or obtained on CDROM for a small service fee. Documentation for all GNU software can be
downloaded for free or obtained in book form for a small service fee. The Free
Software Foundation pays its bills from the collection of service fees and the
sale of T-shirts, and exists mostly through volunteer effort. It is based in
Cambridge, MA.
Go
Go is a compiled object-oriented language influenced by C, C++, C#,
and Java.
gopher
Though not as popular as FTP or http, the gopher protocol is implemented by
many browsers and numerous otherprograms and allows the transfer of files
across networks. In some respects it can be thought of as a hybrid between
FTP and http, although it tends not to be as good at raw file transfer as FTP
and is not as flexible as http. The collection of documents available through
gopher is often called "gopherspace", and it should be noted that
gopherspace is older than the web. It should also be noted that gopher is not
getting as much attention as it once did, and surfing through gopherspace is
a little like exploring a ghost town, but there is an interesting VR interface
available for it, and some things in gopherspace still have not been copied
onto the web.
GUI
A graphical user interface is a graphics-based means of communicating with
a program, especially an OS or window manager. In fact, a window manager
can be thought of as a GUI for a CLI OS.
HP-UX
HP-UX is the version of UNIX designed by Hewlett-Packard to work with
their PA-RISC and 68xx based machines.
HTML
The Hypertext Mark-up Language is the language currently most frequently
used to express web pages (although it is rapidly being replaced by XHTML).
Every browser has the built-in ability to understand HTML. Some browsers
can additionally understand Java and browse FTP areas. HTML is a proper
subset of SGML.
http
The hypertext transfer protocol is the native protocol of browsers and is most
typically used to transfer HTMLformatted files. The secure version is called
"https".
23

Hurd
The Hurd is the official GNU OS. It is still in development and is not yet
supported on too many different processors, but promises to be the most
powerful OS available. It (like all the GNU software) is free.
Hz & hertz
Hertz means cycles per second, and makes no assumptions about what is
cycling. So, for example, if a fluorescent light flickers once per jiffy, it has a
60 Hz flicker. More typical for computers would be a program that runs once
per jiffy and thus has a 60 Hz frequency, or larger units of hertz
like kHz, MHz, GHz, or THz.
i18n
Commonly used to abbreviate the word "internationalization". There are
eighteen letters between the "i" and the "n". Similar to (and often used along
with) i18n.
iCalendar
The iCalendar standard refers to the format used to store calendar type
information (including events, to-do items, and journal entries) on
the Internet. iCalendar data can be found on some World-Wide-Web pages or
attached to e-mailmessages.
icon
A small graphical display representing an object, action, or modifier of some
sort.
IDE
Loosely speaking, a disk format sometimes used by MS-Windows, Mac
OS, AmigaOS, and (rarely) UNIX. EIDE is enhanced IDE; it is much faster.
Generally IDE is inferior (but less expensive) to SCSI, but it varies somewhat
with system load and the individual IDE and SCSI components themselves.
The quick rundown is that: SCSI-I and SCSI-II will almost always outperform
IDE; EIDE will almost always outperform SCSI-I and SCSI-II; SCSI-III and
UltraSCSI will almost always outperform EIDE; and heavy system loads give
an advantage to SCSI. Note that although loosely speaking it is just a format
difference, it is deep down a hardware difference.
Inform
A compiled, object-oriented language optimized for creating interactive
fiction.
infrared communications
A device with an infrared port can communicate with other devices at a
distance by beaming infrared light signals. Two incompatible protocols are
used for infrared communications: IrDA and ASK. Many devices support both.
24

Instant Messenger
AOL's Instant Messenger is is a means of chatting over the Internet in realtime. It allows both open group discussions and private conversations. Instant
Messenger uses a different, proprietary protocol from the more standard IRC,
and is not supported on as many platforms.
interactive fiction
Interactive fiction (often abbreviated "IF" or "I-F") is a form of literature
unique to the computer. While the reader cannot influence the direction of a
typical story, the reader plays a more active role in an interactive fiction story
and completely controls its direction. Interactive fiction works come in all the
sizes and genres available to standard fiction, and in fact are not always even
fiction per se (interactive tutorials exist and are slowly becoming more
common).
interpreted
If a program is interpreted, its actual human-readable source is read as it
is run by the computer. This is generally a slower process than if the program
being run has already been compiled.
intranet
An intranet is a private network. There are many intranets scattered all over
the world. Some are connected to theInternet via gateways.
IP
IP is the family of protocols that makes up the Internet. The two most
common flavors are TCP/IP and UDP/IP.
IRC
Internet relay chat is a means of chatting over the Internet in real-time. It
allows both open group discussions and private conversations.
IRC programs are provided by many different companies and will work on
many differentplatforms. AOL's Instant Messenger utilizes a separate
incompatible protocol but is otherwise very similar.
IrDA
The Infrared Data Association (IrDA) is a voluntary organization of various
manufacturers working together to ensure that the infrared
communications between different computers, PDAs, printers, digital
cameras, remote controls, etc. are all compatible with each other regardless
of brand. The term is also often used to designate an IrDA compliant infrared
communications port on a device. Informally, a device able to communicate
via IrDA compliant infrared is sometimes simply said to "have IrDA". There is
also an earlier, incompatible, and usually slower type of infrared
communications still in use called ASK.
25

IRI
An Internationalized Resource Identifier is just a URI with i18n.
IRIX
The variant of UNIX designed by Silicon Graphics, Inc. IRIX machines are
known for their graphics capabilities and were initially optimized
for multimedia applications.
ISDN
An integrated service digital network line can be simply looked at as a digital
phone line. ISDN connections to theInternet can be four times faster than the
fastest regular phone connection, and because it is a digital connection
amodem is not needed. Any computer hooked up to ISDN will typically require
other special equipment in lieu of the modem, however. Also, both phone
companies and ISPs charge more for ISDN connections than regular modem
connections.
ISP
An Internet service provider is a company that provides Internet support for
other entities. AOL (America Online) is a well-known ISP.
Java
A computer language designed to be both fairly lightweight and
extremely portable. It is tightly bound to the web as it is the primary
language for web applets. There has also been an OS based on Java for use
on small hand-held, embedded, and network computers. It is called JavaOS.
Java can be either interpreted or compiled. For web applet use it is almost
always interpreted. While its interpreted form tends not to be very fast, its
compiled form can often rival languages likeC++ for speed. It is important to
note however that speed is not Java's primary purpose -- raw speed is
considered secondary to portabilty and ease of use.
JavaScript
JavaScript (in spite of its name) has nothing whatsoever to do with Java (in
fact, it's arguably more like Newton Scriptthan Java). JavaScript is
an interpreted language built into a browser to provide a relatively simple
means of adding interactivity to web pages. It is only supported on a few
different browsers, and tends not to work exactly the same on different
versions. Thus its use on the Internet is somewhat restricted to fairly
simple programs. On intranets where there are usually fewer browser
versions in use, JavaScript has been used to implement much more complex
and impressive programs.
jiffy
A jiffy is 1/60 of a second. Jiffies are to seconds as seconds are to minutes.
26

joystick
A joystick is a physical device typically used to control objects on a computer
screen. It is frequently used for games and sometimes used in place of
a mouse.
JSON
The JSON is used for data interchange between programs, an area in which
the ubiquitous XML is not too well-suited.JSON is lightweight and works
extremely cleanly with
languages languages including JavaScript, Python, Java, C++, and many
others.
JSON-RPC
JSON-RPC is like XML-RPC but is significantly more lightweight since it
uses JSON in lieu of XML.
KDE
The K desktop environment is a popular free window manager (and much
more -- as its name touts, it is more of a desktop environment) that runs
under X-Windows.
Kerberos
Kerberos is a network authentication protocol. Basically it preserves the
integrity of passwords in any untrusted network (like the Internet).
Kerberized applications work hand-in-hand with sites that support Kerberos to
ensure that passwords cannot be stolen.
kernel
The very heart of an OS is often called its kernel. It will usually (at minimum)
provide some libraries that give programmers access to its various features.
kHz & kilohertz
One kilohertz is equivalent to 1000 hertz. Some older computers have clock
speeds measured in kHz.
l10n
Commonly used to abbreviate the word "localization". There are ten letters
between the "l" and the "n". Similar to (and often used along with) i18n.
LDAP
The Lightweight Directory Access Protocol provides a means of sharing
address book type of information across an intranet or even across the
Internet. Note too that "address book type of information" here is pretty
broad; it often includes not just human addresses, but machine addresses,
printer configurations, and similar.
27

library
A selection of routines used by programmers to make computers do
particular things.
lightweight
Something that is lightweight will not consume computer resources (such
as RAM and disk space) too much and will thus run on less expensive
computer systems.
Linux
Believe it or not, one of the fastest, most robust, and
powerful multitasking OSes is available for free. Linux can bedownloaded for
free or be purchased on CD-ROM for a small service charge. A handful of
companies distribute Linux including Red Hat, Debian, Caldera, and many
others. Linux is also possibly available for more hardware combinations than
any other OS (with the possible exception of NetBSD.
Supported processors include: Alpha, PowerPC, SPARC,x86, and 68xx. Most
processors currently not supported are currently works-in-progress or even
available in beta. For example, work is currently underway to provide support
for PA-RISC, 65xx, StrongARM, and Z80. People have even successfully gotten
Linux working on PDAs. As you may have guessed, Linux can be made
quite lightweight. Linux is a variant of UNIX and as such, most of the
traditional UNIX software will run on Linux. This especially includes
theGNU software, most of which comes with the majority of Linux
distributions. Fast, reliable, stable, and inexpensive, Linux is popular
with ISPs, software developers, and home hobbyists alike.
Lisp
Lisp stands for list processing and is the second oldest computer language in
the world. Being developed in 1959, it lost the title to FORTRAN by only a few
months. It is typically interpreted, but compilers are available for
some platforms. Attempts were made to standardize the language, and the
standard version is called "Common Lisp". There have also been efforts to
simplify the language, and the results of these efforts is another language
called Scheme. Lisp is a fairlyportable language, but is not particularly fast.
Today, Lisp is most widely used with AI software.
load
There are two popular meanings for load. The first means to fetch some data
or a program from a disk and store it inmemory. The second indicates the
amount of work a component (especially a processor) is being made to do.
Logo
Logo is an interpreted language designed by Papert in 1966 to be a tool for
helping people (especially kids) learn computer programming concepts. In
28

addition to being used for that purpose, it is often used as a language for
controlling mechanical robots and other similar devices. Logo interfaces even
exist for building block / toy robot sets. Logo uses a
special graphics cursor called "the turtle", and Logo is itself sometimes called
"Turtle Graphics". Logo is quite portable but not particularly fast. Versions can
be found on almost every computer platform in the world. Additionally, some
other languages (notably some Pascal versions) provide Logo-like interfaces
for graphics-intensive programming.
lossy
If a process is lossy, it means that a little quality is lost when it is performed.
If a format is lossy, it means that putting data into that format (or possibly
even manipulating it in that format) will cause some slight loss. Lossy
processes and formats are typically used for performance or resource
utilization reasons. The opposite of lossy is lossless.
Lua
Lua is a simple interpreted language. It is extremely portable, and free
versions exist for most platforms.
Mac OS
Mac OS is the OS used on Macintosh computers. There are two distinctively
different versions of it; everything prior to version 10 (sometimes
called Mac OS Classic) and everything version 10 or later (called Mac OS X).
Mac OS Classic
The OS created by Apple and originally used by Macs is frequently (albeit
slightly incorrectly) referred to as Mac OSClassic (officially Mac OS Classic is
this original OS running under the modern Mac OS X in emulation.
Mac OScombines the functionality of both an OS and a window manager and
is often considered to be the easiest OS to use. It is partially multitasking but
will still sometimes crash when dealing with a buggy program. It is probably
the second most popular OS, next only to Windows 'XP (although it is quickly
losing ground to Mac OS X) and has excellentdriver support and boasts a fair
selection of games. Mac OS will run on PowerPC and 68xx based machines.
Mac OS X
Mac OS X (originally called Rhapsody) is the industrial strength OS produced
by Apple to run on both PowerPC andx86 systems (replacing what is often
referred to as Mac OS Classic. Mac OS X is at its heart a variant of UNIX and
possesses its underlying power (and the ability to run many of the traditional
UNIX tools, including the GNU tools). It also was designed to mimic other
OSes on demand via what it originally refered to as "boxes" (actually highperformance emulators); it has the built-in capability to run programs written
for older Mac OS (via its "BlueBox", officially called Mac OS Classic) and work
29

was started on making it also run Windows '95 / '98 / ME software (via what
was called its "YellowBox"). There are also a few rumors going around that
future versions may even be able to runNewton software (via the
"GreenBox"). It provides a selection of two window managers builtin: Aqua and X-Windows(with Aqua being the default).
machine language
Machine language consists of the raw numbers that can be directly
understood by a particular processor. Each processor's machine language will
be different from other processors' machine language. Although called
"machine language", it is not usually what people think of when talking
about computer languages. Machine language dressed up with mnemonics to
make it a bit more human-readable is called assembly language.
Macintosh
A Macintosh (or a Mac for short) is a computer system that has Mac OS for
its OS. There are a few different companies that have produced Macs, but by
far the largest is Apple. The oldest Macs are based on the 68xx processor;
somewhat more recent Macs on the PowerPC processor, and current Macs on
the x86 processor. The Macintosh was really the first general purpose
computer to employ a GUI.
MacTel
An x86 based system running some flavor of Mac OS.
mainframe
A mainframe is any computer larger than a small piece of furniture. A modern
mainframe is more powerful than a modern workstation, but more expensive
and more difficult to maintain.
MathML
The Math Mark-up Language is a subset of XML used to represent
mathematical formulae and equations. Typically it is found embedded
within XHTML documents, although as of this writing not all
popular browsers support it.
megahertz
A million cycles per second, abbreviated MHz. This is often used misleadingly
to indicate processor speed, because while one might expect that a higher
number would indicate a faster processor, that logic only holds true within a
given type of processors as different types of processors are capable of doing
different amounts of work within a cycle. For a current example, either a 200
MHz PowerPC or a 270 MHz SPARC will outperform a 300 MHz Pentium.
Merced
30

The Merced is a RISC processor developed by Intel with help from HewlettPackard and possibly Sun. It is just starting to be released, but is intended to
eventually replace both the x86 and PA-RISC processors. Curiously, HP is
recommending that everyone hold off using the first release and instead wait
for the second one. It is expected some day to be roughly as fast as
an Alpha or PowerPC. It is expected to be supported by future versions
of Solaris, Windows-NT, HP-UX, Mac OS X, and Linux. The current semiavailable Merced processor is called the Itanium. Its overall schedule is way
behind, and some analysts predict that it never will really be released in
significant quanitities.
MFM
Loosely speaking, An old disk format sometimes used by CP/M, MS-DOS,
and MS-Windows. No longer too common as it cannot deliver close to the
performance of either SCSI or IDE.
middleware
Software designed to sit in between an OS and applications. Common
examples are Java and Tcl/Tk.
MIME
The multi-purpose Internet mail extensions specification describes a means
of sending non-ASCII data (such as images, sounds, foreign symbols, etc.)
through e-mail. It commonly utilizes bcode.
MMX
Multimedia extensions were built into some x86 CPUs to provide better
performance for certain operations, most notably graphics and sound. It is
similar to AltiVec on the PowerPC CPUs. Like AltiVec, it requires
special software for full performance benefits to be realized.
MOB
A movable object is a graphical object that is manipulated separately from
the background. These are seen all the time in computer games. When
implemented in hardware, MOBs are sometimes called sprites.
Modula-2 & Modula-3
Modula-2 is a procedural language based on Pascal by its original author in
around the 1977 - 1979 time period. Modula-3 is an intended successor that
adds support for object-oriented constructs (among other things). Modula-2
can be either compiled or interpreted, while Modula-3 tends to be just a
compiled language.
MOTD
A message of the day. Many computers (particularly more capable ones) are
configured to display a MOTD when accessed remotely.
31

Motif
Motif is a popular commercial window manager that runs under X-Windows.
Free work-alike versions are also available.
MS-DOS
The DOS produced by Microsoft. Early versions of it bear striking similarities
to the earlier CP/M, but it utilizes simpler commands. It provides only a CLI,
but either OS/2, Windows 3.1, Windows '95, Windows '98, Windows ME,
or GEOSmay be run on top of it to provide a GUI. It only runs on x86 based
machines.
MS-Windows
MS-Windows is the name collectively given to several somewhat
incompatible OSes all produced by Microsoft. They are: Windows CE, Windows
NT, Windows 3.1, Windows '95, Windows '98, Windows ME, Windows 2000,
andWindows XP.
MUD
A multi-user dimension (also sometimes called multi-user dungeon, but in
either case abbreviated to "MUD") is sort of a combination between the
online chatting abilities provided by something like IRC and a role-playing
game. A MUD built with object oriented principles in mind is called a "Multiuser dimension object-oriented", or MOO. Yet another variant is called a
"multi-user shell", or MUSH. Still other variants are called multi-user roleplaying environments (MURPE) and multi-user environments (MUSE). There
are probably more. In all cases the differences will be mostly academic to the
regular user, as the same software is used to connect to all of them. Software
to connect to MUDs can be found for most platforms, and there are
even Java based ones that can run from within a browser.
multitasking
Some OSes have built into them the ability to do several things at once. This
is called multitasking, and has been in use since the late sixties / early
seventies. Since this ability is built into the software, the overall system will
be slowerrunning two things at once than it will be running just one thing. A
system may have more than one processor built into it though, and such a
system will be capable of running multiple things at once with less of a
performance hit.
nagware
Nagware is a variant of shareware that will frequently remind its users to
register.
NetBSD

32

A free variant of Berkeley UNIX available for Alpha, x86, 68xx, PARISC, SPARC, PowerPC, ARM, and many other types of machines. Its emphasis
is on portability.
netiquette
The established conventions of online politeness are called netiquette. Some
conventions vary from site to site or online medium to online medium; others
are pretty standard everywhere. Newbies are often unfamiliar with
the conventional rules of netiquette and sometimes embarrass themselves
accordingly. Be sure not to send that incredibly important e-mail message
before reading about netiquette.
newbie
A newbie is a novice to the online world or computers in general.
news
Usenet news can generally be thought of as public e-mail as that is generally
the way it behaves. In reality, it is implemented by different software and is
often accessed by different programs. Different newsgroups adhere to
different topics, and some are "moderated", meaning that humans will try to
manually remove off-topic posts, especiallyspam. Most established
newsgroups have a FAQ, and people are strongly encouraged to read the FAQ
prior to posting.
Newton
Although Newton is officially the name of the lightweight OS developed by
Apple to run on its MessagePad line ofPDAs, it is often used to mean the
MessagePads (and compatible PDAs) themselves and thus the term "Newton
OS" is often used for clarity. The Newton OS is remarkably powerful; it is
fully multitasking in spite of the fact that it was designed for small machines.
It is optimized for hand-held use, but will readily transfer data to all manner
of desktopmachines. Historically it was the first PDA. Recently Apple
announced that it will discontinue further development of the
Newton platform, but will instead work to base future hand-held devices on
either Mac OS or Mac OS X with some effort dedicated to making the new
devices capable of running current Newton programs.
Newton book
Newton books provide all the functionality of ordinary books but add
searching and hypertext capabilities. The formatwas invented for
the Newton to provide a means of making volumes of data portable, and is
particularly popular in the medical community as most medical references
are available as Newton books and carrying around a one pound Newton is
preferable to carrying around twenty pounds of books, especially when it
comes to looking up something. In addition to medical books, numerous
33

references, most of the classics, and many contemporary works of fiction are
available as Newton books. Most fiction is available for free, most references
cost money. Newton books are somewhat more capable than the similar Palm
DOC; both are specific types of e-books.
Newton Script
A intepreted, object-oriented language for Newton MessagePad computers.
Nimrod
Nimrod is a compiled language influenced by C, C++, and Objective-C with
some object-oriented programming capabilities.
nybble
A nybble is half a byte, or four bits. It is a case of computer whimsy; it only
stands to reason that a small byte should be called a nybble. Some authors
spell it with an "i" instead of the "y", but the "y" is the original form.
object-oriented
While the specifics are well beyond the scope of this document, the term
"object-oriented" applies to a philosophy ofsoftware creation. Often this
philosophy is referred to as object-oriented design (sometimes abbreviated as
OOD), andprograms written with it in mind are referred to as object-oriented
programs (often abbreviated OOP). Programminglanguages designed to help
facilitate it are called object-oriented languages (sometimes abbreviated as
OOL) anddatabases built with it in mind are called object-oriented databases
(sometimes abbreviated as OODB or less fortunately OOD). The general
notion is that an object-oriented approach to creating software starts with
modeling the real-world problems trying to be solved in familiar real-world
ways, and carries the analogy all the way down to structure of the program.
This is of course a great over-simplification. Numerous object-oriented
programming languages exist including: Java, C++, Modula-2, Newton Script,
and ADA.
Objective-C & ObjC
Objective-C (often called "ObjC" for short) is a compiled objectoriented language. Based heavily on C, Objective-C is nearly as fast and can
often be thought of as being just C with added features. Note that it was
developed independently of C++; its object-oriented extensions are more in
the style of Smalltalk. It is however related to Objective-C++.
Objective-C++ & ObjC++
Objective-C++ (often called "ObjC++" for short) is a curious hybrid
of Objective-C and C++, allowing the syntax of both to coexist in the same
source files.
office suite
34

An office suite is a collection of programs including at minimum a word

processor, spreadsheet, drawing program, and minimal database program.
Some common office suites include MS-Office, AppleWorks, ClarisWorks,
GeoWorks, Applixware, Corel Office, and StarOffice.
open source
Open source software goes one step beyond freeware. Not only does it
provide the software for free, it provides the original source code used to
create the software. Thus, curious users can poke around with it to see how it
works, and advanced users can modify it to make it work better for them. By
its nature, open souce software is pretty well immune to all types of
computer virus.
OpenBSD
A free variant of Berkeley UNIX available for Alpha, x86, 68xx, PARISC, SPARC, and PowerPC based machines. Its emphasis is on security.
OpenDocument & ODF
OpenDocument (or ODF for short) is the suite of open, XML-based office
suite application formats defined by theOASIS consortium. It defines
a platform-neutral, non-proprietary way of storing documents.
OpenGL
A low-level 3D graphics library with an emphasis on speed developed by SGI.
OS/2
OS/2 is the OS designed by IBM to run on x86 based machines. It is semicompatible with MS-Windows. IBM's more industrial strength OS is called AIX.
PA-RISC
The PA-RISC is a RISC processor developed by Hewlett-Packard. It is currently
produced only by HP. At the moment only one OS runs on PA-RISC based
machines: HP-UX. There is an effort underway to port Linux to them, though.
Palm DOC
Palm DOC files are quite similar to (but slightly less capable than) Newton
books. They were designed for Palm Pilotsbut can now be read on a couple
other platforms, too. They are a specific type of e-book.
Palm Pilot
The Palm Pilot (also called both just Palm and just Pilot, officially now just
Palm) is the most popular PDA currently in use. It is one of the least capable
PDAs, but it is also one of the smallest and least expensive. While not as full
featured as many of the other PDAs (such as the Newton) it performs what
features it does have quite well and still remains truly pocket-sized.
35

parallel
Loosely speaking, parallel implies a situation where multiple things can be
done simultaneously, like having multiple check-out lines each serving people
all at once. Parallel connections are by their nature more expensive
than serial ones, but usually faster. Also, in a related use of the word,
often multitasking computers are said to be capable of running
multiple programs in parallel.
partition
Sometimes due to hardware limitations, disks have to be divided into smaller
pieces. These pieces are called partitions.
Pascal
Named after the mathematician Blaise Pascal, Pascal is a language designed
by Niklaus Wirth originally in 1968 (and heavily revised in 1972) mostly for
purposes of education and training people how to write computer programs.
It is a typically compiled language but is still usually slower
than C or FORTRAN. Wirth also created a more powerful objectoriented Pascal-like language called Modula-2.
PC-DOS
The DOS produced by IBM designed to work like MS-DOS. Early versions of it
bear striking similarities to the earlierCP/M, but it utilizes simpler commands.
It provides only a CLI, but either Windows 3.1 or GEOS may be run on top of it
to provide a GUI. It only runs on x86 based machines.
PCMCIA
The Personal Computer Memory Card International Association is a
standards body that concern themselves with PC Card technology. Often the
PC Cards themselves are referred to as "PCMCIA cards". Frequently flash
memory can be found in PC card form.
Perl
Perl is an interpreted language extremely popular for web applications.
PET
The Commodore PET (Personal Electronic Transactor) is an early (circa 19771980, around the same time as theApple][) home computer featuring a ROMbased BASIC developed by Microsoft which it uses as a default "OS". It is
based on the 65xx family of processors and is the precursor to the VIC-20.
PETSCII
The PETSCII character set gets its name from "PET ASCII; it is a variant of
the ASCII character set originally developed for the Commodore PET that
swaps the upper and lower case characters and adds over a hundred graphic
characters in addition to other small changes. If you encounter some text
36

that seems to have uppercase where lowercase is expected and vice-versa, it

is probably a PETSCII file.
PHP
Named with a recursive acronym (PHP: Hypertext Preprocessor), PHP provides
a means of creating web pages that dynamically modify themselves on the
fly.
ping
Ping is a protocol designed to check across a network to see if a particular
computer is "alive" or not. Computers that recognize the ping will report back
their status. Computers that are down will not report back anything at all.
pixel
The smallest distinct point on a computer display is called a pixel.
plug-in
A plug-in is a piece of software designed not to run on its own but rather work
in cooperation with a separateapplication to increase that application's
abilities.
point
There are two common meanings for this word. The first is in the geometric
sense; a position in space without size. Of course as applied to computers it
must take up some space in practise (even if not in theory) and it is thus
sometimes synonomous with pixel. The other meaning is related most
typically to fonts and regards size. The exact meaning of it in this sense will
unfortunately vary somewhat from person to person, but will often mean 1/72
of an inch. Even when it does not exactly mean 1/72 of an inch, larger point
sizes always indicate larger fonts.
PowerPC
The PowerPC is a RISC processor developed in a collaborative effort between
IBM, Apple, and Motorola. It is currently produced by a few different
companies, of course including its original developers. A few
different OSes run on PowerPC based machines, including Mac
OS, AIX, Solaris, Windows NT, Linux, Mac OS X, BeOS, and AmigaOS. At any
given time, the fastest processor in the world is usually either a PowerPC or
an Alpha, but sometimes SPARCs andPA-RISCs make the list, too.
proprietary
This simply means to be supplied by only one vendor. It is commonly
misused. Currently, most processors are non-proprietary, some systems are
non-proprietary, and every OS (except for arguably Linux) is proprietary.
protocol
37

A protocol is a means of communication used between computers. As long as

both computers recognize the same protocol, they can communicate without
too much difficulty over the same network or even via a simple
direct modemconnection regardless whether or not they are themselves of
the same type. This means that WinTel boxes, Macs,Amigas, UNIX machines,
etc., can all talk with one another provided they agree on a common protocol
first.
Psion
The Psion is a fairly popular brand of PDA. Generally, it is in between
a Palm and a Newton in capability. It runs theEPOC OS.
Python
Python is an interpreted, object-oriented language popular
for Internet applications. It is extremely portable with free versions existing
for virtually every platform.
queue
A queue is a waiting list of things to be processed. Many computers provide
printing queues, for example. If something is being printed and
the user requests that another item be printed, the second item will sit in the
printer queue until the first item finishes printing at which point it will be
removed from the queue and get printed itself.
QuickDraw
A high-level 3D graphics library with an emphasis on quick development time
created by Apple.
RAM
Random access memory is the short-term memory of a computer. Any
information stored in RAM will be lost if power goes out, but the computer can
read from RAM far more quickly than from a drive.
random access
Also called "dynamic access" this indicates that data can be selected without
having to skip over earlier data first. This is the way that a CD, record,
laserdisc, or DVD will behave -- it is easy to selectively play a particular track
without having to fast forward through earlier tracks. The other common
behavior is called sequential access.
RDF
The Resource Description Framework is built upon an XML base and provides
a more modern means of accessing data from Internet resources. It can
provide metadata (including annotations) for web pages making (among
other things) searching more capable. It is also being used to refashion some
existing formats like RSS and iCalendar; in the former case it is already in
38

place (at least for newer RSS versions), but it is still experimental in the latter
case.
real-time
Something that happens in real-time will keep up with the events around it
and never give any sort of "please wait" message.
Rexx
The Restructured Extended Executor is an interpreted language designed
primarily to be embedded in other applications in order to make them
consistently programmable, but also to be easy to learn and understand.
RISC
Reduced instruction set computing is one of the two main types of processor
design in use today, the other being CISC. The fastest processors in the world
today are all RISC designs. There are several popular RISC processors,
includingAlphas, ARMs, PA-RISCs, PowerPCs, and SPARCs.
robot
A robot (or 'bot for short) in the computer sense is a program designed to
automate some task, often just sending messages or collecting information. A
spider is a type of robot designed to traverse the web performing some task
(usually collecting data).
robust
The adjective robust is used to describe programs that are better designed,
have fewer bugs, and are less likely to crash.
ROM
Read-only memory is similar to RAM only cannot be altered and does not lose
its contents when power is removed.
RSS
RSS stands for either Rich Site Summary, Really Simple Syndication,
or RDF Site Summary, depending upon whom you ask. The general idea is
that it can provide brief summaries of articles that appear in full on
a web site. It is well-formed XML, and newer versions are even more
specifically well-formed RDF.
Ruby
Ruby is an interpreted, object-oriented language. Ruby was fairly heavily
influenced by Perl, so people familiar with that language can typically
transition to Ruby easily.
Rust

39

Rust is a compiled language inspired by not just languages like C but also
more unusual languages like Haskell and Erlang.
scanner
A scanner is a piece of hardware that will examine a picture and produce a
computer file that represents what it sees. Adigital camera is a related
device. Each has its own limitations.
Scheme
Scheme is a typically interpreted computer language. It was created in 1975
in an attempt to make Lisp simpler and more consistent. Scheme is a
fairly portable language, but is not particularly fast.
script
A script is a series of OS commands. The term "batch file" means much the
same thing, but is a bit dated. Typically the same sort of situations in which
one would say DOS instead of OS, it would also be appropriate to say batch
file instead of script. Scripts can be run like programs, but tend to perform
simpler tasks. When a script is run, it is alwaysinterpreted.
SCSI
Loosely speaking, a disk format sometimes used by MS-Windows, Mac
OS, AmigaOS, and (almost always) UNIX. Generally SCSI is superior (but more
expensive) to IDE, but it varies somewhat with system load and the individual
SCSI and IDE components themselves. The quick rundown is that: SCSI-I and
SCSI-II will almost always outperform IDE; EIDE will almost always outperform
SCSI-I and SCSI-II; SCSI-III and UltraSCSI will almost always outperform EIDE;
and heavy system loads give an advantage to SCSI. Note that although
loosely speaking it is just a format difference, it is deep down
a hardware difference.
sequential access
This indicates that data cannot be selected without having to skip over earlier
data first. This is the way that a cassette or video tape will behave. The other
common behavior is called random access.
serial
Loosely speaking, serial implies something that has to be done linearly, one
at a time, like people being served in a single check-out line. Serial
connections are by their nature less expensive than parallel connections
(including things like SCSI) but are typically slower.
server
A server is a computer designed to provide various services for an
entire network. It is typically either a workstation or a mainframe because it
will usually be expected to handle far greater loads than
40

ordinary desktop systems. The load placed on servers also necessitates that
they utilize robust OSes, as a crash on a system that is currently being used
by many people is far worse than a crash on a system that is only being used
by one person.
SGML
The Standard Generalized Mark-up Language provides an extremely
generalized level of mark-up. More common mark-up languages
like HTML and XML are actually just popular subsets of SGML.
shareware
Shareware is software made for profit that allows a trial period before
purchase. Typically shareware can be freelydownloaded, used for a period of
weeks (or sometimes even months), and either purchased or discarded after
it has been learned whether or not it will satisfy the user's needs.
shell
A CLI designed to simplify complex OS commands. Some OSes (like AmigaOS,
the Hurd, and UNIX) have built-in support to make the concurrent use of
multiple shells easy. Common shells include the Korn Shell (ksh), the Bourne
Shell (sh or bsh), the Bourne-Again Shell, (bash or bsh), the C-Shell (csh), etc.
SIMM
A physical component used to add RAM to a computer. Similar to, but
incompatible with, DIMMs.
Smalltalk
Smalltalk is an efficient language for writing computer programs. Historically
it is one of the first object-orientedlanguages, and is not only used today in
its pure form but shows its influence in other languages like Objective-C.
Solaris
Solaris is the commercial variant of UNIX currently produced by Sun. It is an
industrial strength, nigh bulletproof, powerful multitasking OS that will run
on SPARC, x86, and PowerPC based machines.
spam
Generally spam is unwanted, unrequested e-mail or Usenet news. It is
typically sent out in bulk to huge address lists that were automatically
generated by various robots endlessly searching the Internet and newsgroups
for things that resemble e-mail addresses. The legality of spam is a topic of
much debate; it is at best only borderline legal, and spammers have been
successfully persecuted in some states.
SPARC
41

The SPARC is a RISC processor developed by Sun. The design was more or
less released to the world, and it is currently produced by around a dozen
different companies too numerous to even bother mentioning. It is worth
noting that even computers made by Sun typically sport SPARCs made by
other companies. A couple different OSes run on SPARC based machines,
including Solaris, SunOS, and Linux. Some of the newer SPARC models are
called UltraSPARCs.
sprite
The term sprite originally referred to a small MOB, usually implemented
in hardware. Lately it is also being used to refer to a single image used
piecemeal within a Web site in order to avoid incurring the time penalty of
downloading multiple files.
SQL
SQL (pronounced Sequel) is an interpreted language specially designed
for database access. It is supported by virtually every major modern
database system.
Sugar
The window manager used by the OLPC XO. It is made to run on top of Linux.
SunOS
SunOS is the commercial variant of UNIX formerly produced (but still
supported) by Sun.
SVG
Scalable Vector Graphics data is an XML file that is used to hold graphical
data that can be resized without loss of quality. SVG data can be kept in its
own file, or even embedded within a web page (although not all browsers are
capable of displaying such data).
Tcl/Tk
The Tool Command Language is
a portable interpreted computer language designed to be easy to use. Tk is
a GUItoolkit for Tcl. Tcl is a fairly popular language for both integrating
existing applications and for creating Web applets(note that applets written in
Tcl are often called Tcklets). Tcl/Tk is available for free for most platforms,
and plug-insare available to enable many browsers to play Tcklets.
TCP/IP
TCP/IP is a protocol for computer networks. The Internet is largely built on top
of TCP/IP (it is the more reliable of the two primary Internet Protocols -- TCP
stands for Transmission Control Protocol).
terminator
42

A terminator is a dedicated device used to mark the end of a device chain (as
is most typically found with SCSIdevices). If such a chain is not properly
terminated, weird results can occur.
TEX
TEX (pronounced "tek") is a freely available, industrial strength
typesetting program that can be run on many differentplatforms. These
qualities make it exceptionally popular in schools, and
frequently software developed at a university will have its documentation in
TEX format. TEX is not limited to educational use, though; many professional
books were typeset with TEX. TEX's primary drawback is that it can be quite
difficult to set up initially.
THz & terahertz
One terahertz is equivalent to 1000 gigahertz.
TrackBack
TrackBacks essentially provide a means whereby different web sites can post
messages to one another not just to inform each other about citations, but
also to alert one another of related resources. Typically, a blog may display
quotations from another blog through the use of TrackBacks.
UDP/IP
UDP/IP is a protocol for computer networks. It is the faster of the two
primary Internet Protocols. UDP stands for UserDatagram Protocol.
Unicode
The Unicode character set is a superset of the ASCII character set with
provisions made for handling international symbols and characters from other
languages. Unicode is sixteen bit, so takes up roughly twice the space as
simple ASCII, but is correspondingly more flexible.
UNIX
UNIX is a family of OSes, each being made by a different company or
organization but all offering a very similar look and feel. It can not quite be
considered non-proprietary, however, as the differences between different
vendor's versions can be significant (it is still generally possible to switch
from one vendor's UNIX to another without too much effort; today the
differences between different UNIXes are similar to the differences between
the different MS-Windows; historically there were two different UNIX camps,
Berkeley / BSD and AT&T / System V, but the assorted vendors have worked
together to minimalize the differences). The free variant Linux is one of the
closest things to a current, non-proprietary OS; its development is controlled
by a non-profit organization and its distribution is provided by several
companies. UNIX is powerful; it is fully multitasking and can do pretty much
anything that any OS can do (look to theHurd if you need a more powerful
43

OS). With power comes complexity, however, and UNIX tends not to be overly
friendly to beginners (although those who think UNIX is difficult or cryptic
apparently have not used CP/M). Window managers are available for UNIX
(running under X-Windows) and once properly configured common operations
will be almost as simple on a UNIX machine as on a Mac. Out of all the OSes
in current use, UNIX has the greatest range of hardware support. It will run on
machines built around many different processors. Lightweight versions of
UNIX have been made to run on PDAs, and in the other direction, full featured
versions make full advantage of all the resources on large, multi-processor
machines. Some different UNIX versions
include Solaris, Linux, IRIX, AIX, SunOS, FreeBSD, Digital UNIX, HPUX, NetBSD, OpenBSD, etc.
upload
To upload a file is to copy it from your computer to a remote computer. The
opposite is download.
UPS
An uninterrupted power supply uses heavy duty batteries to help smooth out
its input power source.
URI
A Uniform Resource Identifier is basically just a unique address for almost
any type of resource. It is similar to but more general than a URL; in fact, it
may also be a URN.
URL
A Uniform Resource Locator is basically just an address for a file that can be
given to a browser. It starts with aprotocol type (such as http, ftp, or gopher)
and is followed by a colon, machine name, and file name in UNIX style.
Optionally an octothorpe character "#" and and arguments will follow the file
name; this can be used to further define position within a page and perform a
few other tricks. Similar to but less general than a URI.
URN
A Uniform Resource Name is basically just a unique address for almost any
type of resource unlike a URL it will probably not resolve with a browser.
USB
A really fast type of serial port that offers many of the best features
of SCSI without the price. Faster than many types ofparallel port, a single USB
port is capable of chaining many devices without the need of a terminator.
USB is much slower (but somewhat less expensive) than FireWire.
uucode
44

The point of uucode is to allow 8-bit binary data to be transferred through the
more common 7-bit ASCII channels (most especially e-mail). The facilities for
dealing with uucoded files exist for many different machine types, and the
most common programs are called "uuencode" for encoding the original
binary file into a 7-bit file and "uudecode" for restoring the original binary file
from the encoded one. Sometimes different uuencode and uudecode
programs will work in subtly different manners causing annoying
compatibility problems. Bcode was invented to provide the same service as
uucode but to maintain a tighter standard.
variable width
As applied to a font, variable width means that different characters will have
different widths as appropriate. For example, an "i" will take up much less
space than an "m". The opposite of variable width is fixed width. The terms
"proportional width" and "proportionally spaced" mean the same thing as
variable width. Some common variable width fonts include Times, Helvetica,
and Bookman.
VAX
The VAX is a computer platform developed by Digital. Its plural is VAXen.
VAXen are large expensive machines that were once quite popular in large
businesses; today modern UNIX workstations have all the capability of VAXen
but take up much less space. Their OS is called VMS.
vector
This term has two common meanings. The first is in the geometric sense: a
vector defines a direction and magnitude. The second concerns
the formatting of fonts and images. If a font is a vector font or an image is a
vector image, it is defined as lines of relative size and direction rather than as
collections of pixels (the method used in bitmapped fonts and images). This
makes it easier to change the size of the font or image, but puts a
bigger load on the device that has to display the font or image. The term
"outline font" means the same thing as vector font.
Veronica & Veronica2
Although traditionally written as a proper name, Veronica is actually an
acronym for "very easy rodent-orientednetwide index
to computerized archives", where the "rodent" refers to gopher. The acronym
was obviously a little forced to go along with the pre-existing (and now
largely unused) Archie, in order to have a little fun with a comic book
reference. Regardless, Veronica (or these days more likely Veronica2) is
essentially a search engine for gopher resources.
VIC-20
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The Commodore VIC-20 computer sold millions of units and is generally

considered to have been the first affordable home computer. It features
a ROM-based BASIC and uses it as a default "OS". It is based on
the 65xx family ofprocessors. VIC (in case you are wondering) can stand for
either video interface c or video interface computer. The VIC-20 is the
precursor to the C64/128.
virtual machine
A virtual machine is a machine completely defined and implemented
in software rather than hardware. It is often referred to as a "runtime
environment"; code compiled for such a machine is typically called bytecode.
virtual memory
This is a scheme by which disk space is made to substitute for the more
expensive RAM space. Using it will often enable a comptuer to do things it
could not do without it, but it will also often result in an overall slowing down
of the system. The concept of swap space is very similar.
virtual reality
Virtual reality (often called VR for short) is generally speaking an attempt to
provide more natural, human interfaces tosoftware. It can be as simple as a
pseudo 3D interface or as elaborate as an isolated room in which the
computer can control the user's senses of vision, hearing, and even smell and
touch.
virus
A virus is a program that will seek to duplicate itself in memory and on disks,
but in a subtle way that will not immediately be noticed. A computer on the
same network as an infected computer or that uses an infected disk (even
afloppy) or that downloads and runs an infected program can itself become
infected. A virus can only spread to computers of the same platform. For
example, on a network consisting of a WinTel box, a Mac, and a Linux box, if
one machine acquires a virus the other two will probably still be safe. Note
also that different platforms have different general levels of
resistance; UNIX machines are almost immune, Win '95 / '98 / ME / XP is quite
vulnerable, and most others lie somewhere in between.
VMS
The industrial strength OS that runs on VAXen.
VoIP
VoIP means "Voice over IP" and it is quite simply a way of utilizing
the Internet (or even in some cases intranets) for telephone conversations.
The primary motivations for doing so are cost and convenience as VoIP is
significantly less expensive than typical telephone long distance packages,
plus one high speed Internet connection can serve for multiple phone lines.
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VRML
A Virtual Reality Modeling Language file is used to represent VR objects. It
has essentially been superceded by X3D.
W3C
The World Wide Web Consortium (usually abbreviated W3C) is a non-profit,
advisory body that makes suggestions on the future direction of the World
Wide Web, HTML, CSS, and browsers.
Waba
An extremely lightweight subset of Java optimized for use on PDAs.
WebDAV
WebDAV stands for Web-based Distributed Authoring and Versioning, and is
designed to provide a way of editing Web-based resources in place. It serves
as a more modern (and often more secure) replacement for FTP in many
cases.
WebTV
A WebTV box hooks up to an ordinary television set and displays web pages.
It will not display them as well as a dedicated computer.
window manager
A window manager is a program that acts as a graphical go-between for
a user and an OS. It provides a GUI for the OS. Some OSes incorporate the
window manager into their own internal code, but many do not for reasons of
efficiency. Some OSes partially make the division. Some common true window
managers include CDE (Common Desktop Environment), GNOME, KDE, Aqua,
OpenWindows, Motif, FVWM, Sugar, and Enlightenment. Some common
hybrid window managers with OS extensions include Windows ME, Windows
98, Windows 95, Windows 3.1, OS/2 andGEOS.
Windows '95
Windows '95 is currently the second most popular variant of MS-Windows. It
was designed to be the replacementWindows 3.1 but has not yet done so
completely partly because of suspected security problems but even more
because it is not as lightweight and will not work on all the machines that
Windows 3.1 will. It is more capable than Windows 3.1 though and now has
excellent driver support and more games available for it than any other
platform. It is made to run on top of MS-DOS and will not do much of anything
if MS-DOS is not on the system. It is thus not strictly an OSper se, but nor is it
a true window manager either; rather the combination of MS-DOS and
Windows '95 result in a full OS with GUI. It is partially multitasking but has a
much greater chance of crashing than Windows NT does (or probably
even Mac OS) if faced with a buggy program. Windows '95 runs only
on x86 based machines. Currently Windows '95 has several Y2K issues, some
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of which have patches that can be downloaded for free, and some of which
do not yet have fixes at all.
Windows '98
Windows '98 is quite possibly the second most popular form of MS-Windows,
in spite of the fact that its official release is currently a point of legal debate
with at least nineteen states, the federal government, and a handful of
foreign countries as it has a few questionable features that might restrict the
novice computer user and/or unfairly compete with other computer
companies. It also has some specific issues with the version of Java that
comes prepackaged with it that has never been adequately fixed, and it still
has several Y2K issues, most of which have patches that can
be downloadedfor free (in fact, Microsoft guarantees that it will work properly
through 2000 with the proper patches), but some of which do not yet have
fixes at all (it won't work properly through 2001 at this point). In any case, it
was designed to replace Windows '95.
Windows 2000
Windows 2000 was the intended replacement for Windows NT and in that
capacity received relatively lukewarm support. Being based on Windows NT,
it inherits some of its driver support problems. Originally it was also supposed
to replace Windows '98, but Windows ME was made to do that instead, and
the merger between Windows NT and Windows '98 was postponed
until Windows XP.
Windows 3.1
Windows 3.1 remains a surprisingly popular variant of MS-Windows. It
is lighter weight than either Windows '95 orWindows NT (but not lighter
weight than GEOS) but less capable than the other two. It is made to run on
top of MS-DOS and will not do much of anything if MS-DOS is not on the
system. It is thus not strictly an OS per se, but nor is it a true window
manager, either; rather the combination of MS-DOS and Windows 3.1 result in
a full OS with GUI. Itsdriver support is good, but its game selection is limited.
Windows 3.1 runs only on x86 based machines. It has some
severe Y2K issues that may or may not be fixed.
Windows CE
Windows CE is the lightweight variant of MS-Windows. It offers the general
look and feel of Windows '95 but is targetted primarily for hand-held
devices, PDAs, NCs, and embedded devices. It does not have all the features
of either Windows '95 or Windows NT and is very different from Windows 3.1.
In particular, it will not run any software made for any of the other versions of
MS-Windows. Special versions of each program must be made. Furthermore,
there are actually a few slightly different variants of Windows CE, and no
variant is guaranteed to be able to run software made specifically for another
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one. Driver support is also fairly poor for all types, and few games are made
for it. Windows CE will run on a few different processor types, including
the x86 and several different processors dedicated to PDAs, embedded
systems, and hand-held devices.
Windows ME
Windows ME is yet another flavor of MS-Windows (specifically the planned
replacement for Windows '98). Windows ME currently runs only on
the x86 processor.
Windows NT
Windows NT is the industrial-strength variant of MS-Windows. Current
revisions offer the look and feel of Windows '95 and older revisions offer the
look and feel of Windows 3.1. It is the most robust flavor of MS-Windows and
is fullymultitasking. It is also by far the most expensive flavor of MS-Windows
and has far less software available for it than Windows '95 or '98. In
particular, do not expect to play many games on a Windows NT machine, and
expect some difficulty in obtaining good drivers. Windows NT will run on a few
different processor types, including the x86, theAlpha, and the PowerPC.
Plans are in place to port Windows NT to the Merced when it becomes
available.
Windows Vista
Windows Vista is the newest flavor of MS-Windows (specifically the planned
replacement for Windows XP). Windows Vista (originally known as Longhorn)
currently only runs on x86 processors.
Windows XP
Windows XP is yet another flavor of MS-Windows (specifically the planned
replacement for both Windows ME andWindows 2000). Windows XP currently
only runs on the x86 processors. Windows XP is currently the most popular
form of MS-Windows.
WinTel
An x86 based system running some flavor of MS-Windows.
workstation
Depending upon whom you ask, a workstation is either an industrial
strength desktop computer or its own category above the desktops.
Workstations typically have some flavor of UNIX for their OS, but there has
been a recent trend to call high-end Windows NT and Windows
2000 machines workstations, too.
WYSIWYG

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What you see is what you get; an adjective applied to a program that
attempts to exactly represent printed output on the screen. Related
to WYSIWYM but quite different.
WYSIWYM
What you see is what you mean; an adjective applied to a program that
does not attempt to exactly represent printed output on the screen, but
rather defines how things are used and so will adapt to different paper sizes,
etc. Related toWYSIWYG but quite different.
X-Face
X-Faces are small monochrome images embedded in headers for both
provides a e-mail and news messages. Better mail and news applications will
display them (sometimes automatically, sometimes only per request).
X-Windows
X-Windows provides a GUI for most UNIX systems, but can also be found as
an add-on library for other computers. Numerous window managers run on
top of it. It is often just called "X".
X3D
Extensible 3D Graphics data is an XML file that is used to hold threedimensional graphical data. It is the successor toVRML.
x86
The x86 series of processors includes the Pentium, Pentium Pro, Pentium II,
Pentium III, Celeron, and Athlon as well as the 786, 686, 586, 486, 386, 286,
8086, 8088, etc. It is an exceptionally popular design (by far the most
popular CISCseries) in spite of the fact that even its fastest model is
significantly slower than the assorted RISC processors. Many
different OSes run on machines built around x86 processors, including MSDOS, Windows 3.1, Windows '95, Windows '98, Windows ME, Windows
NT, Windows 2000, Windows CE, Windows
XP, GEOS, Linux, Solaris, OpenBSD,NetBSD, FreeBSD, Mac OS
X, OS/2, BeOS, CP/M, etc. A couple different companies produce x86
processors, but the bulk of them are produced by Intel. It is expected that this
processor will eventually be completely replaced by theMerced, but the
Merced development schedule is somewhat behind. Also, it should be noted
that the Pentium III processor has stirred some controversy by including a
"fingerprint" that will enable individual computer usage of web pages etc. to
be accurately tracked.
XBL
An XML Binding Language document is used to associate executable content
with an XML tag. It is itself an XML file, and is used most frequently (although
not exclusively) in conjunction with XUL.
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XHTML
The Extensible Hypertext Mark-up Language is essentially a cleaner, stricter
version of HTML. It is a proper subset ofXML.
XML
The Extensible Mark-up Language is a subset of SGML and a superset
of XHTML. It is used for numerous things including (among many
others) RSS and RDF.
XML-RPC
XML-RPC provides a fairly lightweight means by which one computer can
execute a program on a co-operating machine across a network like
the Internet. It is based on XML and is used for everything from fetching stock
quotes to checking weather forcasts.
XO
The energy-efficient, kid-friendly laptop produced by the OLPC project. It
runs Sugar for its window manager andLinux for its OS. It sports numerous
built-in features like wireless networking, a video camera & microphone, a
fewUSB ports, and audio in/out jacks. It comes with several
educational applications (which it refers to as "Activities"), most of which are
written in Python.
XSL
The Extensible Stylesheet Language is like CSS for XML. It provides a means
of describing how an XML resource should be displayed.
XSLT
XSL Transformations are used to transform one type of XML into another. It is
a component of XSL that can be (and often is) used independently.
XUL
An XML User-Interface Language document is used to define a user interface
for an application using XML to specify the individual controls as well as the
overall layout.
Y2K
The general class of problems resulting from the wrapping of computers'
internal date timers is given this label in honor of the most obvious
occurrence -- when the year changes from 1999 to 2000 (abbreviated in
some programs as 99 to 00 indicating a backwards time movement).
Contrary to popular belief, these problems will not all manifest themselves on
the first day of 2000, but will in fact happen over a range of dates extending
out beyond 2075. A computer that does not have problems prior to the
beginning of 2001 is considered "Y2K compliant", and a computer that does
not have problems within the next ten years or so is considered for all
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practical purposes to be "Y2K clean". Whether or not a given computer is

"clean" depends upon both its OS and its applications (and in some
unfortunate cases, its hardware). The quick rundown on common home /
small business machines (roughly from best to worst) is that:

All Mac OS systems are okay until at least the year 2040. By that time
a patch should be available.

All BeOS systems are okay until the year 2040 (2038?). By that time a
patch should be available.

Most UNIX versions are either okay or currently have free fixes
available (and typically would not have major problems until 2038 or
later in any case).

NewtonOS has a problem with the year 2010, but has a free fix
available.

Newer AmigaOS systems are okay; older ones have a problem with the
year 2000 but have a free fix available. They also have a year 2077
problem that does not yet have a free fix.

Some OS/2 systems have a year 2000 problem, but free fixes are
available.

All CP/M versions have a year 2000 problem, but free fixes are
available.

PC-DOS has a year 2000 problem, but a free fix is available.

DR-DOS has a year 2000 problem, but a free fix is available.

Different versions of GEOS have different problems ranging from minor

year 2000 problems (with fixes in the works) to larger year 2080
problems (that do not have fixes yet). The only problem that may not
have a fix in time is the year 2000 problem on the Apple ][ version of
GEOS; not only was that version discontinued, unlike the other GEOS
versions it no longer has a parent company to take care of it.

All MS-Windows versions (except possibly Windows 2000 and Windows

ME) have multiple problems with the year 2000 and/or 2001, most of
which have free fixes but some of which still lack free fixes as of this
writing. Even new machines off the shelf that are labelled "Y2K
Compliant" usually are not unless additional software is purchased and
installed. Basically WinNT and WinCE can be properly
patched, Windows '98 can be patched to work properly through 2000
(possibly not 2001), Windows '95 can be at least partially patched for
52

2000 (but not 2001) but is not being guaranteed by Microsoft,

and Windows 3.1 cannot be fully patched.

MS-DOS has problems with at least the year 2000 (and probably more).
None of its problems have been addressed as of this writing. Possible
fixes are to change over to either PC-DOS or DR-DOS.

Results vary wildly for common applications, so it is better to be safe than

sorry and check out the ones that you use. It should also be noted that some
of the biggest expected Y2K problems will be at the two ends of the computer
spectrum with older legacy mainframes (such as power some large banks)
and some of the various tiny embedded computers (such as power most
burgler alarms and many assorted appliances). Finally, it should also be
mentioned that some olderWinTel boxes and Amigas may have Y2K problems
in their hardware requiring a card addition or replacement.
Z-Machine
A virtual machine optimized for running interactive fiction, interactive
tutorials, and other interactive things of a primarily textual nature. ZMachines have been ported to almost every platform in use today. Zmachine bytecode is usually called Z-code. The Glulx virtual machine is of the
same idea but somewhat more modern in concept.
Z80
The Z80 series of processors is a CISC design and is not being used in too
many new stand-alone computer systems, but can still be occasionally found
in embedded systems. It is the most popular processor for CP/M machines.
Zaurus
The Zaurus is a brand of PDA. It is generally in between a Palm and
a Newton in capability.
zip
There are three common zips in the computer world that are completely
different from one another. One is a type of removable
removable disk slightly larger (physically) and vastly larger (capacity) than
a floppy. The second is a group of programs used for running interactive
fiction. The third is a group of programs used for compression.
Zoomer
The Zoomer is a type of PDA. Zoomers all use GEOS for their OS and are /
were produced by numerous different companies and are thus found under
numerous different names. The "classic" Zoomers are known as the Z-7000,
the Z-PDA, and the GRiDpad and were made by Casio, Tandy, and AST
respectively. Newer Zoomers include HP's OmniGo models, Hyundai's Gulliver
53

(which may not have actually been released to the general public), and
Nokia's Communicator line of PDA / cell phone hybrids.

54