Appendix A


ACK  In data communications, a report that a packet or message has been received correctly.

AIFF  Audio IFF, developed by Apple Computer for storing high-quality sampled sound.

ALIWEB  A search engine, available at http://web.

allocate  To grant a resource, such as memory, to a requesting program.

Anarchie  (pronounced like anarchy), a Macintosh client for both FTP and Archie. Anarchie is available at and

ANSI  American National Standards Institute, a major U.S. standards-setting organization.

Apache  A popular UNIX-based Web server, available at

API  Application Program Interface; a specification for functions, routines, and data available from a library or program shared or integrated with another program.

applications  Software designed and written for the purpose of solving a problem or creating a Web-based environment through dynamic page generation or system tasks.

AS/400  A popular mid-range computer from IBM.

associative array  A list of unordered elements, in which each element is the relationship between a key and value.

asynchronous  Used to describe the multitude of individual events that occurs simultaneously and without relation to other events except within a larger closed system.

back end  The system-level support that is unseen by the client user but provides the Web server, database, and external services to help create the interfaces that are available to the client user.

Bambi  The name used on the Internet by David Hughes, author of miniSQL.

bastion host  A computer that serves as the key point of a firewall.

BCS  Bandwidth Conservation Society, a Web site ( dedicated to helping Web developers keep graphics small.

binary structure  The arrangement of data in which the boundaries between atomic data types are nonexistent. The data is interpreted at the bit level. The meaning of the data contained in a binary structure is interpreted only by the specific application.

bounce   To return e-mail to the sender as undeliverable, or in Majordomo, to send a message to the list owner for special approval because the message violates certain rules.

browser  A software application that allows a user to look up information on the Internet, primarily the World Wide Web.

BrowserCaps  A Web site ( that lists browser capabilities.

BrowserWatch  A Web site ( that lists the browsers that visitors have used.

buffer  A temporary storage area for information, usually for a short period and in the order in which the information was received.

cache  To store a copy of something, usually for fast local access; also, the storage space used for caching.

CCITT  Comite Consultatif International Telephonique et Telegraphique, the international standards-setting organization for telephony and data communications.

CERT  Computer Emergency Response Team, an Internet-wide security organization that helps stop computer crime.

CGI  Common Gateway Interface, a mechanism that allows Web users to access non-Web programs.

CGI sandwich  A slang term that describes the program wrapper around a static HTML file. A CGI script skeleton that reads in a static HTML file and dumps it back.

CGM  Computer Graphics Metafile, a file format that accommodates both vector and raster images in a single file.

chat room  An area of Web space that allows people to exchange messages online.

client pull  Technology developed for the Web environment that allows a page to reload automatically when the client requests new pages. The client software must be capable of recognizing the special tags that are added to HTML for this purpose.

CMM  Capability Maturity Model, a multiple-layer description of software engineering process maturity developed at the Software Engineering Institute.

CMYK  The color model used for the printed page, based on the colors cyan, magenta, yellow, and black.

COAST  Computer Operations and Security Technology, a research program at Purdue University. The COAST Web site is at

COCOMO  Constructive Cost Model, a cost model of the software-development process documented in the book Software Engineering Economics, by Barry Boehm (Prentice-Hall, 1981).

color quantization  The process of allocating true colors to indexed colors.

Common Log Format  The format of the access log used by NCSA, Apache, and many other Web servers.

companding  A method of compressing high-level signals and enhancing or expanding low-level signals.

concurrent masking  The phenomenon that keeps a listener from hearing softer sounds if a louder sound is present at a nearby frequency.

Configuration Control System  Software that assigns and maintains version numbers and typically allows only one person to have a writable copy of a document. Also known as a Version Control System and a Configuration Management System.

conforming  In a PostScript program, a term that indicates compliance with the conventions of the Adobe Document Structuring Committee.

cookie  A mechanism developed by Netscape for preserving data on a client's hard drive between HTTP transactions.

COPS  Computer Oracle and Password System, a set of programs that attempts to find security holes in file permissions and configuration files. COPS includes the Kuang Rule-based Security Checker. Available from

Crack  A password cracker, available at misc/volumn28, that is useful to a system administrator who wants to find out which accounts have poorly chosen passwords.

cwnd  Congestion window, a parameter used by TCP/IP slow start; part of TCP.

daemon  A program that is left running in the background, waiting for a particular set of circumstances (such as a request) to trigger it into action.

database  A system of applications and data that stores information (retrievable via a query interface) in a persistent, stable, and organized fashion.

DBM  A disk-based associative array, popular in UNIX and implemented directly in Perl.

DBMS  Database Management System, a mechanism for storing data in files and accessing it with a high-level language. Also see SQL and RDBMS.

DCT  Discrete Cosine Transform, used in JFIF and MPEG compression schemes.

deallocate  To release control of memory that was previously allocated.

DeBabelizer  A Macintosh program renowned for its capability to integrate color maps for several images.

DECnet  A networking protocol defined by Digital Equipment Corporation (DEC).

dithering  The process of approximating on-screen a color that is not available in the color table.

DNS  Domain Name System, a system that translates between human-readable domain names and machine-usable IP addresses.

document root  The directory in the Web server's file system that is the beginning of the file tree of documents available from the Web server. In the URL, for example, the trailing slash (/) signifies the document root.

downward expansion  See noise gating.

DSC  Adobe's Document Structuring Committee, the committee that defines conventions for PostScript programs.

Dual-Homed Gateway  A firewall topology in which one machine is attached directly to the Internet and the LAN.

DVE  Digital Video Effects, the process of introducing special effects into a video by controlling two or more videotape recorders with a computer.

dwell time  In Web log analysis, the period of time that a user spends viewing a page. Dwell time is estimated from the time between page accesses.

dynamic HTML  A Web page that is built on the fly. See dynamically generated and static HTML file.

dynamically generated  Made at runtime by the invocation of scripts or programs that are ultimately requested by a user or the programmed/scheduled events supported by the Web server. A feedback-acknowledgment page is dynamically generated. A sports-score page that updates after every new score, independently of the user, is also dynamically generated.

EDL  Edit Decision List, a list showing which pieces of videotape will be used to produce the video master. Also see offline editing and online editing.

environment variables  The shell data components of a process in the UNIX environment.

environments  Places within a Web site where the associations between pages lead to the belief that the pages have a common theme to explore or use for a specific purpose. A Web chat environment, for example, is a set of pages that supports the chat model.

EPS  Encapsulated PostScript, a self-contained PostScript program that draws an image; also known as EPSF.


FDF  Form Definition File, the file used in WDB to integrate the database and the Web form.

file system  The hardware and software component of an operating system that manages the access and management needs of electronic files.

filtering  Removing or dynamically editing content for the Web for censorship reasons.

firewall  A computer and software that attempt to protect a LAN from penetration attempts from the Internet.

flat  Lacking any internal structure.

flat-ASCII  Said of a text file that contains only 7-bit ASCII characters and uses only ASCII-standard control characters. Also known as plain-ASCII.

flat file  A flattened representation of some database, tree, or network structure as a single file from which the structure could implicitly be rebuilt, especially one in flat-ASCII form.

flatten  To remove structural information, especially to filter something with an implicit hierarchical structure into a simple sequence; also tends to imply mapping to flat-ASCII.

flush  To discard all remaining data in an input or output device. But in C and UNIX, the fflush(3) call forces buffered disk I/O to complete. These two meanings are logically opposite.

freeWAIS  A descendant of the original WAIS, available over the Net.

FTP  File Transfer Protocol, part of the TCP/IP family of protocols. Anonymous FTP is a common way of offering files to the public.

gecos  Personal data, such as name and phone number, stored in the UNIX /etc/passwd file.

GET  An access method in HTTP.

GLIMPSE  Global Implicit Search, one of the most powerful WAIS-like systems available.

Gopher  An older standard for serving text-based, nonhyperlinked documents.

half-close  The method used by either participant in a TCP connection to shut down the conversation.

handle  Nickname or moniker used by someone who is participating in a multiple-user environment or left as a signature on an electronic message.

HARVEST  A powerful Net-based search and retrieval system developed at the University of Colorado.

helper application  An application invoked by a Web browser for MIME types that the browser cannot handle internally. Also see plug-in.

hidden type  A special kind of variable, declared by the <INPUT> tag, that does not appear in the client's Web browser.

hits  The number of times that a component of a Web page is accessed.

HPGL  Hewlett-Packard Graphics Language.

HTML form  An HTML construction that includes the <FORM> tag declaration with one or many <INPUT> tags, with the purpose of collecting data to be passed as input to a CGI program.

HTTP  HyperText Transfer Protocol, the protocol of the World Wide Web.

httpd  The HTTP daemon, the UNIX name for the Web server.

IEEE  Institute of Electrical and Electronics Engineers, an international professional group and standards-setting organization.

IESG  Internet Engineering Steering Group. This is a committee formed to help the IETF chair.

IETF  Internet Engineering Task Force, this is the group that develops the specifications that become Internet standards.

IFD  Image File Directories, part of the TIFF standard.

imagemap  A graphic set up to allow a user's click to select different pages or programs, depending on where the click is on the graphic. It is customary to associate hot spots on the graphic with specific files or programs. Imagemaps can be implemented on the client or on the server.

Incident Response Team  A team formed by an organization to respond to attacks on computer security.

inetd  A UNIX daemon that provides Internet service management for a network.

IndexedFaceSet  The VRML node used to build three-dimensional objects of arbitrary shape.

Internet  The world-wide interconnection of networks to form the network of networks. The Internet originally was a research project for the U.S. Department of Defense called the ARPANET; now, it is mostly organized for commercial and educational purposes.

Inventor (or Open Inventor)  The SGI language on which VRML is based.

IP  Internet Protocol, one of the communications protocols of the Internet. IP usually is specified as part of a family known as TCP/IP.

IP address  Four 8-bit numbers used to uniquely identify every machine on the Internet. An IP address usually is written with dots between the numbers, as in

IPC  Inter-Process Communication, the mechanisms by which software processes talk with one another. Typical UNIX IPC mechanisms include shared memory, pipes, semaphores, and message queues.

IRC  Internet Relay Chat, a protocol and application that enable users around the Internet to chat real-time in groups.

ISAM  Indexed Sequential Access Method, a database mechanism by which indexes point to disk blocks or similar physical storage locations, rather than directly to the record.

ISO  International Standards Organization, an international standards-setting organization.

ISOC  Internet Society, a professional society to facilitate, support, and promote the evolution and growth of the Internet as a global research communications infrastructure.

ISP  Internet Service Provider, an organization that provides access (usually dial-up) to the Internet.

JFIF  JPEG File Interchange Format (commonly referred to as JPEG), a popular image format for Web pages.

join  In an RDBMS, to answer a query by building records from multiple tables.

JPEG  Joint Photographic Experts Group; also, the common name for the JFIF image standard.

kerning  In typesetting, directions for controlling the spacing between characters.

Kuang Rule-Based Security Checker  An expert system, included in COPS, that tries to find links from the outside world to the UNIX superuser account.

lag  A seemingly random delay experienced online.

LAN  Local Area Network, a collection of computers at one physical location or campus which share resources, and their internetworking hardware and software. See also WAN.

list server  A server set up to distribute mail to the users whose names appear in a defined list.


local guide  The manual or documentation, assembled for users, that describes the custom software and tools installed.

logging  In video postproduction, the process of cataloging and reviewing all raw material before editing and assembling the finished work.

login  The process by which a user gains access to a computer system. On a UNIX system, the software that prompts the user to login.

lurking  Spending a great deal of time reading or replying privately within a very public forum. A lurker on UseNet, for example, reads almost all the articles for a long period, rarely or never posts to the newsgroup.

LZW  Lempel-Ziv-Welch compression algorithm, an algorithm protected by patents owned by Unisys.

Majordomo  A popular list server, written in Perl.

make  A utility used to generate an output file based on changes in a set of component files.

markup language  A syntax and procedure for embedding in text documents tags that control formatting when the documents are viewed by a special application. A Web browser interprets HTML (HyperText Markup Language).

MIB  Management Information Base, a set of information about network elements used by SNMP.

MIME  Multimedia Internet Mail Extensions, a mechanism used by e-mail and Web servers to tell a client what type of content is being sent so that the client can interpret the data correctly.

mirror site  A Web site set up to be an exact copy of another, to better serve users who are geographically far from the master site.

MNP  Microcom Networking Protocol, a set of protocols for error detection, correction, and data compression. Largely superseded by V.42 and V.42bis.

morphing  The mechanism by which an image in a video sequence can be made to appear to change into another image.

Morris Worm  A program that attacked the Internet in November 1988, forcing many sites to leave the Net temporarily.

Mozilla  The internal name of the Netscape browser.

MPEG  Moving Pictures Experts Group; also, the audio and video compression standards developed by that group.

mSQL  miniSQL, a subset of SQL and the RDBMS that implements it, written by David Hughes. mSQL costs a fraction of the price of the commercial RDBMSs but offers those elements of SQL that are most often needed on the Web. mSQL is therefore quite popular among Webmasters.

MSS  Maximum Segment Size, a parameter used in the TCP.

MTA  Mail Transfer Agent, the program that actually handles e-mail transactions with a remote host. See also SMTP.

MUD  Multiuser Dimension, a type of multiple-user game environment, in which players participate socially and create new areas to explore from within the game.

multitasking  Performing more than one task at the same time. Multitasking is a feature of some operating systems, such as UNIX.

NAK  In data communications, a report that a packet or message has been received in garbled form; usually interpreted as a request for retransmission.

navigation  The act of traversing a chain of hypertext links from a starting point to a final result.

NCSA  National Center for Supercomputer Applications, which developed the NCSA Server, a popular UNIX-based Web server. Visit NCSA's Web site at http://hoohoo.

Netscape Communications Corporation  Developer of a popular browser (Netscape Navigator) and two commercial UNIX-based Web servers: Netscape Communications Server (described at and Netscape Commerce Server (described at

Netscape Navigator  A popular Web browser by Netscape Communications Corporation.

newsgroup  One of the UseNet's collection of topic groups, such as comp.infosystems.www.announce. The name is a hierarchical structure.

NFS  Network File System, a mechanism that allows disk drives on one machine to be used across the network on another machine.

NIS  Network Information Service (formerly known as Yellow Pages), a system by which one machine (the master) holds the ethernet addresses of other machines (the servants). NIS is an insecure alternative to DNS.

NIST  U.S. National Institute of Standards and Technology, formerly known as the National Bureau of Standards.

NNTP  Network News Transfer Protocol, the mechanism by which UseNet is propagated around the world.

noise gating  A mechanism for reducing sound levels between pauses; used to control quantization noise.

Nyquist Theorem  A principle in physics that says that to reproduce a signal, one must sample that signal at a rate at least twice the highest frequency in the signal.

offline editing  The process of preparing Edit Decision Lists (EDLs) for use during online editing.

OILZ Worm  The successor to the WANK Worm. See also WANK Worm.

online editing  The process of implementing Edit Decision Lists (EDLs) on the actual video material.

operating system  A collection of software written to provide the fundamental instructions that a computer needs to manage resources, such as memory, the file system, and processes.

PATH  An environment variable used to list directories that should be searched for a given file.

path matching  Part of the cookie mechanism, allowing multiple cookies per server.

PCL  Hewlett-Packard Printer Control Language, an HP-proprietary language used to render pages on Hewlett-Packard printers.

PDL  Page Description Language, a generic term encompassing PostScript and Hewlett-Packard's PDL.

PEM  Privacy Enhanced Mail, a public key encryption system defined by Internet RFCs.

Perl  Practical Extraction and Report Language (also Pathologically Eclectic Rubbish Lister), a rich language developed by Larry Wall. Perl is often used to implement CGI scripts.

PERL  The interpreter for Perl, typically located on a UNIX system at /usr/bin/perl.

PGP  Pretty Good Privacy, a public-key encryption utility developed by Phil Zimmerman. PGP is widely used on the Internet.

PHP/FI  An embedded scripting language that is capable of providing access to mSQL from an HTML page.

ping  A TCP/IP protocol used to verify a connection between two machines.

PIP  In the PSP, a Process Improvement Proposal.

plug-in  A technology developed by Netscape and now adopted by some other Web browser vendors to handle certain MIME types inside the browser environment, instead of with a helper application.

PNG  Portable Network Graphic, an alternative to GIF for Web graphics.

Porter stemming algorithm  An algorithm built into waisindex and waisserver to allow stemming. See also stemming.

POST  An access method in HTTP.

postmasking  The phenomenon that occurs when an abrupt shift in sound causes the listener to not hear softer sounds that occur just after the shift.

premasking  The phenomenon that occurs when an abrupt shift in sound causes the listener to not hear low-level sounds that occur just before the shift.

PROBE  Proxy-Based Estimating, an estimating method documented in the book A Discipline for Software Engineering, by Watts Humphrey (Addison-Wesley, 1995).

proof of concept  A prototype that is built to show that the technique, system design, or marketability of a proposed application or system is likely to be as good as expected.

proxy server  A server that acts as both a client and a server; used for security, convenience, or caching.

PSP  Personal Software Process, a set of process recommendations developed by Watts Humphrey of the Software Engineering Institute.

PUT  An access method in HTTP.

quantization  The process of converting an analog signal (such as the voltage associated with sound) to a number.

QUERY_STRING  The environment variable which contains the information passed to a CGI script by means of GET.

QuickTime  Apple Computer's standard for time-based material, such as video, sound, and multimedia sequences. Available for Windows and UNIX computers as well as Macintoshes.

race condition  A logical situation in which the outcome depends upon which of two or more competing processes is granted a resource first. Considered undesirable since race conditions lead to nondeterministic behavior.

RAIC  Redundant Array of Inexpensive Computers, one way to scale a site.

rcp  A UNIX-to-UNIX utility for copying files over the Net.

RCS  Revision Control System, a UNIX-based Configuration Control System.

RDBMS  Relational Database Management System, a database mechanism in which the user's logical view of the data is based on tables (also known as relations). Also see mSQL.

real-time  Describes an application which requires a program to respond to stimuli within some small upper limit of response time (typically milli- or microseconds).

relevance ranking  A ranking that gives extra weight to a document when the search terms appear in the headline or are capitalized.

reloading  The act of requesting a page from a Web server which is already visible in the Web browser. The purpose of reloading is mainly to verify changes in documents or to reinvoke certain actions (such as CGI scripts) on the Web server.

RFC  Request for Comment, the place where all of the official standards in the Internet community are published.

RGB  Red-Green-Blue, the most common color model for computer-based images.

.rhosts  A file on a UNIX machine that allows a user to declare another machine to be "trusted." If a known user logs in from a trusted machine, that user is granted access without being asked again for a password.

RIFF WAVE  An audio format, commonly known as WAV.

RJE  Remote Job Entry, a method of running batch programs on some computers.

RLE  Run-Length Encoding, a simple but powerful compression algorithm used in GIF and other formats.

RPC  Request for Comment. Documents widely circulated by the IETF, many of which form the official standards of the Internet.

rsh  A UNIX-to-UNIX utility for starting a remote login session or executing a command on a remote machine.

RTT  Round-Trip Time, the amount of time that it takes a packet to go from one computer to another and for the acknowledgment to be returned.

S-HTTP  Secure HTTP, an application-level encryption scheme developed by Enterprise Integration Technologies.

SATAN  Security Administrators Tool for Analyzing Networks, a set of small tools, run as a suite, that identify and report potential security holes in a UNIX system.

scale  The process of adding resources to a system, such as a Web server, to handle a heavier load. See also RAIC.

SCCS  Source Configuration System, a UNIX-based Configuration Control System.

schema  The relational or object-oriented design and layout of specific data.

Screened Host Gateway  A firewall topology in which one machine (the bastion host) monitors transactions between the LAN and the Internet.

script  A program that runs on the Web server, written in an interpreted language such as Perl or Tcl.

SEI  Software Engineering Institute, a research center at Carnegie-Mellon University.

semaphore  A mechanism for restricting access to critical sections of code to a single user or process at a time.

Server Push  Technology developed for the Web environment that allows a page to reload automatically when the server generates new content. The MIME type used for Server Push is multipart/x-mixed.

SGI  Silicon Graphics Inc., a major vendor of open systems.

showmount  The UNIX utility that displays information about the NFS.

SIGHUP  The hang-up signal. In UNIX, SIGHUP is commonly used to tell a daemon to reread its configuration files. Signals are sent in UNIX with the kill command.

signal-to-noise ratio  "Signal" refers to that portion of communications that carries meaning. "Noise" refers to everything else in the communications channel. Thus signal-to-noise ratio, also called s/n ratio or SNR, is a measure of the available content compared to useless energy. In addition to its technical meaning, often used on the Internet to refer to the ratio of on-topic content to off-topic traffic in a UseNet newsgroup or mailing list discussion group.

skeleton  A program that contains the proper header and footer declarations but lacks actual code to perform a task; also, a file stub that provides the framework for the details of the program to be inserted.

SLOC  Source Line of Code, one line in a computer program. In many languages, each SLOC ends with a semicolon. SLOC is used in COCOMO and PROBE as the basis for estimating software-development time.

SMTP  Simple Mail Transfer Protocol, the protocol used by mail transfer agents to send and receive e-mail over the Internet.

SNMP  Simple Network Management Protocol, the member of the TCP/IP family that allows communications and control of network elements by managers.

SQL  (pronounced see-quel) Structured Query Language, an ANSI-standard language for accessing databases.

SSI  Server-side includes, a method by which Web pages can include small pieces of information that is not directly stored in their file.

SSL  Secure Socket Layer, a low-level encryption scheme developed by Netscape.

SSLeay  A free implementation of SSL.

static HTML file  An HTML document that is represented and stored as a file under the Web server's document root. A static HTML file can be changed or updated only by editing the file. See also dynamic HTML.

STDERR  Standard Error, a file handle open for output by default in many operating systems and languages, typically used for program error messages.

STDIN  Standard Input, a file handle open for input by default in many operating systems and languages, typically used for program input.

STDOUT  Standard Output, a file handle open for output by default in many operating systems and languages, typically used for program output.

stemming  An algorithm that allows a document that contains a certain word (for example, informing) to match a query for a related term (for example, informs).

storyboard  A set of mockups (as of Web pages or animation frames) that serves to capture the concept and content of a yet-to-be-produced production version.

stripe  (of a disk volume) To distribute a logical volume over more than one physical volume; to decrease the time required to access files.

SWISH  Simple Web Indexing System for Humans, a full-text indexing system logically related to WAIS.

TA  Technical Assistant, a staff position that supports technical or management personnel. Many Technical Assistants go on to become programmers or engineers.

TAMU Tiger  A security program that is similar to COPS and Tripwire combined. The program is available from Texas A&M University at

TCP  Transmission Control Protocol, one of the communications protocols of the Internet. TCP usually is specified as part of a family known as TCP/IP. TCP connections are set up by using a three-way handshake to ensure the delivery of every packet.

text box  An area of a Web page, usually created with <INPUT> tags, that accepts a single line of input.

TFTP  Trivial File Transfer Protocol, a member of the TCP/IP family of protocols; used by diskless hosts to obtain their startup information.

thread  Also known as a topic thread-a more or less continuous stream of postings to a newsgroup or discussion list on a single topic.

TIFF  Tag Image File Format, a popular high-end file format for images.

time stamp  Time of day, encapsulated in an alphanumeric quantity for registering an event. When files are modified, their "last modified" time stamp is updated with a new time.

time-to-live  The number of routers through which an IP packet can pass before it is discarded.

toolbar  A compact textual or graphical region of a page that contains hypertext links to other parts of the site or the Web.

traceroute  A TCP/IP protocol used to identify the components of the path between two machines and to identify the contribution of each component to the overall Round-Trip Time.

Tripwire  A computer program from COAST that detects and reports changes in key system files.

Trojan Horse  A program that looks like a standard utility but contains hidden code that is designed to open a security hole into the target computer system.

TSR  Terminate-and-Stay Resident, a limited form of multitasking that is available to MS-DOS users.

UART  Universal Asynchronous Receiver-Transmitter, the chip in a computer that permits serial communications.

UDP  User Datagram Protocol, one of the communications protocols of the Internet. UDP usually is specified as part of a family known as TCP/IP. UDP is very fast but does not guarantee delivery of every packet.

uptime  A command in the UNIX environment that tells the number of days a server has been running since the last shutdown.

URI  Uniform Resource Identifier. URLs are a type of URI.

URL  Uniform Resource Locator, the address of an Internet resource, such as a Web page.

UseNet  Network community built around the distribution of articles posted to thousands of newsgroups worldwide.

V.42  Link Access Procedure for Modems (LAP-M), an error-control protocol from CCITT.

V.42bis  Data-compression algorithms from the CCITT.

VCR  Videocassette recorder; also known as a videotape recorder.

virtual host  A Web server configuration in which different IP addresses point to different document roots, allowing more than one Web site to be supported on the same computer.

virtual reality  Simulation of real-life experiences, usually through the use of graphical display devices and sensitive input devices worn by all participants.

VPATH  A variable recognized by some versions of make, telling that utility where to look for files.

VRML  Virtual Reality Modeling Language, a modeling language in which three-dimensional objects, their surfaces, and their lighting sources are described. Such models can be served over the Web and are read using VRML browsers.

WAIS  Wide Area Information Server, software that allows multiple indexes to be searched over wide area networks.

WAN  Wide Area Network, a collection of computers that are geographically distributed but share resources and their internetworking hardware and software. See also LAN.

WANK Worm  A program that attacked components of the Internet in October and November 1989, playing practical jokes on users. The WANK Worm was followed by the OILZ Worm.

WDB  A set of programs, written by Bo Frese Rasmussen, that generate HTML forms and reports based on the contents of an RDBMS, such as mSQL.

Web server  A machine (or set of machines) connected to the network that runs software that supports the HTTP requests for documents from client machines.

Webmaster  The person who usually maintains the content and operational status of a Web server.

WebStar  A popular Macintosh-based Web server, formerly known as MacHTTP. The server is described at

World Wide Web  A network of hosts on the Internet that share data and information with the public (or private groups) through the transfer of documents via the HTTP protocol.

worm  A virus-like program that transfers itself from one machine to another over the Internet. The term often is used to refer to the Morris Worm.

W3-mSQL  A set of commands that can be embedded in an HTML file and are interpreted by a program written by David Hughes, author of miniSQL. W3-mSQL is an excellent way to access an mSQL database from a Web page.

W3C  World Wide Web Consortium.

XBM  X Bit Maps, a simple graphics standard used in the X Windows system.

xinted  A less insecure replacement for the UNIX inetd daemon, available at