Instant Messaging (IM)
Another way to carry out a conversation with someone over the Internet is to use
for short. To use instant messaging, you need to have an instant messaging client program installed on your system. There are a number of instant messaging
for one or more variants of UNIX, including Gaim
(for Linux, BSD, Mac, and OS X), Kopete (the KDE Instant Messenger)
(for Linux and BSD), Eb-Lite
(for Linux), Sun Java System Instant Messaging
(for Solaris, Mac OS X, Linux, and HP-UX). These programs are available for free downloading. Using a client program, you can set up a connection to one or more instant messaging services. IM clients
support a large number of different IM services. We will
discuss one of these clients, Gaim, here.
instant messaging client program called
(named after a fictional alien race from Babylon 5) is available for free download. Gaim was originally written by Mark Spencer; it now runs on Linux, BSD, and Mac OS X, as well as on
. Gaim is compatible with many different instant messaging systems, including the AOL Instant Messenger, MSN Messenger, Yahoo! Messenger, and Jabber, as well as IRC. Using Gaim, you can log in to multiple accounts on multiple IM networks at the same line. For example, using Gaim you can
chat with a friend on AOL Instant Messenger and talk with a different friend on Yahoo! Messenger, while you participate in an IRC channel.
Gaim provides tabbed message windows for switching among different conversations. It supports a wide array of features, including many features of different IM services. In particular, Gaim supports file transfer, buddy icons, away messages, typing notification, and MSN window closing notification. Using the Buddy Pounces feature of Gaim, when a particular buddy signs on, goes away, or returns from idle, you can have the program notify you, send you a message, play a sound, or run a program.
For more information about Gaim, go to the official Gaim home page at
The World Wide Web
Hundreds of millions of people using the World Wide Web everyday. But what is the web? The
short for the
World Wide Web,
is a global network connecting millions of documents, called
stored as files on computers called
Web servers often contain groups of web pages that together make up a
Web pages are formatted using a special language, HTML (
anguage), discussed later in this book. Web users view these files using a client program called a
which has become a crucial software program for personal computers.
The web is based on a client/server model. The client runs browser software that allows a
to request information on the web and to browse and navigate through it to pick out useful information. The information that you request is stored on a machine called a
The function of the web server is to provide
web documents, pages, and applications to multiple simultaneous browser
. We will discuss web servers further in Chapter 16.
To view information on the web, you use a program known as a browser, which is a program running on a client machine. Your browser is your user interface as you navigate through the World Wide Web. You provide your browser with the address of a web site (in the form of a Uniform Resource Locator (URL) described later in this chapter). The browser then
to obtain the web page you
over the Internet. If the browser successfully fetches this page, you can then view information on that page and navigate to locations both on the page and those linked to other pages, through what is referred to as a