        Introduction 

In a Nutshell

As soon as you have NCSA Mosaic for the X Window System 
working (See How to Install on page11), there is one thing 
you need to know: 

To navigate the web of information, single click your left 
mouse button on the words or images shown in color or 
underlined, which are the hyperlinks between documents. 

Mosaic Capabilities

NCSA Mosaic software is a distributed hypermedia system 
designed for information discovery and retrieval over the 
Internet, which is a global network of networks. NCSA Mosaic 
provides a single interface to the variety of protocols, data for-
mats, and information servers available throughout the Inter-
net. 

NCSA Mosaic includes the following features:

       display of plain text, rich text, and hypermedia

       inline graphics and images

       a customizable graphical user interface

       global history of information space navigationtracking 
where youve been

       quick access to important or frequently used documents 
via a personal hotlist

       search capabilities within a document and over the Inter-
net

       text and voice annotation for documents anywhere on the 
Internet

       full TCP/IP-based communications support

       easily extendable to arbitrary viewers or other data for-
mats

NCSA Mosaic is implemented for three platforms: Macintosh, 
Microsoft Windows, and the X Window System on UNIX sys-
tems.

The Web and Hypermedia

The World Wide Web (Web) originated at CERN, the particle 
physics institute in Geneva, Switzerland. The Web, sometimes 
abbreviated WWW, is a worldwide hypermedia information 
space providing ready access to a variety of documents con-
tained on servers connected to the Internet. In this case, docu-
ment refers to a file of any type (e.g., text, graphic, video) that 
can be stored on a Web server and viewed by Web client soft-
ware.

Hypermedia organizes information as an interconnected web 
of associations rather than as a linear sequence (which you 
find in a book). Scattered within a hypermedia document are 
hyperlinks (words or images that are highlighted) to other 
related documents. Clicking on a hyperlink brings up a new 
document. In turn, that document links to others, and so it 
goes.

Most documents available on Web servers are linked, meaning 
that hyperlinks embedded in the documents connect all the 
documents in some way. For example, NCSA Mosaic documen-
tation contains links to documents on the NCSA Web server as 
well to documents on servers maintained by other universities 
and research laboratories. Those Web servers have documents 
that, in turn, link to other documents on other servers.

Servers and Clients

NCSA Mosaic uses a client/server model. Some computers are 
configured to communicate with other computers and offer 
services, such as providing documents or search mechanisms. 
The machines that provide the services and the document 
files are called servers. A workstation runs client software, 
such as NCSA Mosaic for the X Window System, that requests 
services and provides the interface between the server 
machine and the user. Together the client and server provide 
information and the way to access that information. 

Server software, using the HyperText Transfer Protocol 
(HTTP), is also available from NCSA. See System Configura-
tion and Modification Assistance on pageC1 for informa-
tion.

NCSA

Established in 1985 with a National Science Foundation grant, 
the National Center for Supercomputing Applications (NCSA) 
opened to the national research community in January 1986. 
NCSA is a high-performance computing and communications 
facility designed to serve U.S. computational science and engi-
neering communities. Located on the campus of the University 
of Illinois at Urbana-Champaign (UIUC), NCSA is funded by the 
National Science Foundation, the Advanced Research Projects 
Agency, other federal agencies, the state of Illinois, the Univer-
sity of Illinois, and industrial partners.

NCSA Mosaic Software Developers

NCSA Mosaic is a product of the NCSA Software Development 
Group (SDG). SDG develops workstation software programs to 
assist in scientific discovery, including software for data anal-
ysis and visualization. SDG develops tools for all of the major 
platforms: Macintoshes, PCs, UNIX workstations, and high-end 
supercomputers.

Most SDG tools are available on the NCSA anonymous FTP 
server (ftp.ncsa.uiuc.edu).

Notational Conventions

Material in this manual is presented in text, screen displays, or 
command-line notation. Different typefaces indicate different 
functions.

New concepts or terms are generally in italic type when they 
first occur in text to indicate that they are defined in the para-
graph.

Cross references within this manual usually include the title of 
the referenced section or chapter enclosed in quotation marks 
(e.g., see Exploring on Your Own on page 5-4).

Boldface type represents characters you enter as shown (lit-
eral expressions).

Lowercase italic type represents a variable, a placeholder for 
the text you actually enter. A variable can consist of different 
characters each time you make the entry.

Throughout this manual, you may be instructed to enter spe-
cific characters on the keyboard. These entry instructions 
(command lines) are printed in fixed-width boldface type (e.g., 
dothis) and appear either within a paragraph or on a separate 
line. Command lines are normally entered in lowercase.

San-serif boldface type (e.g., the Cancel button) represents 
boxes and buttons in dialog boxes, command names on pull-
down menus, menu names, and hyperlinks.

Keys that are labeled on your keyboard with more than one 
character, such as the RETURN key, are identified by all upper-
case letters in normal font. Keys that you are to press simulta-
neously or in succession are linked with a hyphen (e.g., press 
SHIFT-OPTION-d).
