The World Wide Web is a service found on the Internet, and is based
upon a client-server model. The World Wide Web is a hypertext document
system that is based on a client-server model: a client (browser)
requests and retrieves documents from servers (computers) connected
to the Internet.
Browsers use URLs (Uniform Resource Identifier's) to locate documents
(webpages) stored on servers: a URL is a string of characters that
identify an Internet resource. Alongside locating and retrieving
documents (webpages), browsers also render and display the document
and can also (potentially) interact with it.
Browsers can access and navigate (also known as surfing)
the World Wide Web through a number of means:
1. Direct input of a URL into the address bar of a browser.
2. By clicking on a hyperlink
- also referred to as 'link'.
a list of saved URLs.
When a URL is inputted into a browser: the browser uses the Hypertext
Transfer Protocol (HTTP) to validate and access the document (webpage).
HTTP will request the help of TCP (Transmission Control Protocol)
to retrieve the document (webpage) located at the server the URL
suggests it is at.
Documents (webpages) located on the World Wide Web are designed
using HTML (HyperText Markup Language). HTML is a hypertext language
that uses elements to "build" a document. Browsers render
HTML elements differently; therefore, a webpage will not look identical
in every browser.
In 1990, the first web browser was developed by Tim Berners-Lee,
and released publicly in 1991: when the World Wide Web was launched
on the 6th of August, 1991. Berners-Lee invented the World Wide
Web while he worked at CERN (a European center for physics research).
The name of Berners-Lee's browser was 'WorldWideWeb'.
The WorldWideWeb was a basic text only browser, and, by 1992, a
range of browsers were being developed to improve upon it's functionality
and platform compatibility. Provided below, is a list of early web
browsers that were developed from 1991-1992.
- MacWWW: the first browser developed
for the Apple Macintosh platform.
- Line Mode Browser: expanded
the compatibility of the WorldWideWeb browser.
- Lynx: Developed by team of students
at the University of Kansas.
- ViolaWWW: Developed by Pei-Yuan
Wei, released on March 9, 1992.
- MidasWWW: Developed at the (SLAC)
Stanford Linear Accelerator Center.
- Cello: The first browser developed
for the Microsoft Windows operating system.
- Erwise: Developed by students of the
Helsinki University of Technology.
The first browser to obtain widespread popularity was NCSA
Mosaic. Mosaic was designed at the National Center for Supercomputing
Applications (NCSA), and, by a team of software engineers that included
Marc Andreessen and Eric Bina. Mosaic is acclaimed for helping to
popularise the web. Mosaic was originally designed to run on the
Unix platform, and, only at a later date was it released for the
Apple Macintosh and the Microsoft Windows platform.
Why was Mosaic first released on Unix? In the early 1990's the
Internet was only just beginning to be commercially deregulated
and most households (in developed nations) did not have access to
the Internet. Therefore, operating systems, like Windows, did not
focus heavily on encouraging network access. From 1990-1994, Unix
was the most popular operating system, used, to access the Internet.
However, by the mid 1990's, interest in the Internet expanded,
and many commercial Internet Service Providers began offering access
to home users. Due to Windows being the dominant domestic operating
system: the vast majority of home users connected to the Internet
using Windows instead of Unix. This trend has continued to the present
day (2014), and has resulted in software developers primarily designing
browsers for the Windows platform.
Due to the success of Mosaic, the Mosaic Communications Corporation
was created on the 4th of April, 1994. The Mosaic Communications
Corporation hired the majority of software engineers who helped
to design the original Mosaic browser. The first browser released
by the Mosaic Communications Corporation was Mosaic Netscape 0.9.
Eventually, the Mosaic Communications Corporation was renamed to
the Netscape Communications Corporation,
and the browser renamed to the Netscape
In the mid-1990s, the Netscape Navigator was the most popular browser,
but, the Netscape Communications Corporation would soon be embroiled
in a fierce battle with Microsoft, who released Internet Explorer
and packaged it with Windows 95. Netscape accused Microsoft of an
illegal monopolistic action by "giving away" (packaging)
Internet Explorer with the Windows operating system. The whole "furor"
eventually resulted in a lawsuit (United States v. Microsoft Corporation,
for committing monopolization - 253 F.3d 34), but, it did not stop
Internet Explorer from becoming the preeminent web browser.
From 1997-2010, Internet Explorer has been the dominant web browser
used by Windows computers. Apple released the Safari browser in
2003, and this browser, likewise, has been the dominant web browser
used by Macintosh computers. While browsers have been released for
other platforms - Unix, Linux, Amiga - they are niche browsers in
terms of overall usage share (combined under 2% of overall browser
Present Day (2014-Onwards)
Since 2010, Internet Explorer faced stiff competition from a selection
of three new browsers: Opera, Chrome, and Firefox. As of 2014, 'rough'
estimates of browser usage are:
- Chrome: 30%
- Internet Explorer: 22%
- Firefox: 19%
- Safari: 15%
- Opera: 6%
- Android: 5%
- Others: 3%
Mozilla Firefox and Google Chrome are the two browsers that have
eaten into Microsoft's market share. The two ongoing criticisms
of Internet Explorer have been it's size and security flaws. What
is notable about the above numbers: is that browsers designed principally
for the Windows and Macintosh platforms continue to monopolise web
However, it is interesting to note that Android (a browser developed
for mobile devices) has taken
a sizable market share. From 2014 onwards, many technology experts
are predicting that mobile devices - and therefore mobile browsers
- will continue to increase in their use. Safari, for example, is
also a mobile browser, alongside being a traditional browser, and
accounts for upwards of 60% of all mobile browser usage.
While web browsers make a point of being compatible
with the majority of web content, they are not exclusively cross
platform. The earliest web browsers were primarily compatible
with Unix: in the early 1990's, Unix was the most popular operating
system for Internet users. As Internet usage expanded in the 1990's,
the majority of Internet users were using Windows instead of Unix:
therefore, software developers began to focus on developing browsers
for Windows instead of Unix.
While browsers are usually designed and targeted for a specific
platform (operating system) they are typically written in the C++
- Chrome - written in C/C++, Python
- Firefox - written in C/C++
- Internet Explorer- written in C++
- Opera - written in C++
- Safari - written in C++ and Objective-C
Since the early 1990's, the features available in browsers have
steadily evolved. The Mosaic browser is acclaimed for popularising
the web, and invented many of the principle features found in modern
browsers. The image, shown below, is the GUI of Mosaic:
The characteristics of the Mosaic GUI - with it's URL address
bar, history manager, tools - is still maintained by modern
browsers. It is generally accepted that Netscape Navigator and Internet
Explorer copied the layout and features of Mosaic; however, that
is to be expected with Netscape Navigator, as it was developed by
the same team of developers that created Mosaic - Marc
Andreessen et al.
One of the important dates in browser development is the 23rd of
February, 1998: this is the day that Netscape created Mozilla. Mozilla
is a combination of the words: Mosaic and Godzilla. Mozilla is a
community/corporation/foundation that manages the development of
the open source release of Netscape
Communicator (successor to Netscape Navigator). Mozilla released
Firefox in 2002. Firefox continues the legacy of Netscape Navigator,
and in some senses the Mosaic browser.
Browser Functions and Features
Web browsers tend to include the following standard features (menu
1. Address bar (command line
2. Back, forward, stop, refresh,
and home buttons.
3. Bookmarks (favourites in Internet Explorer) and history.
The primarily function of a web browser is to fetch and retrieve
web content (webpages). Therefore, it comes as no surprise that
the features highlighted above primarily deal with locating web
content. Browsers locate web content using a Uniform Resource Locator
(URL), and URL's are used within the three features shown above.
Browsers support a range of fonts; the
default font is usually: Arial. Browsers support a range of plug-ins,
the most obvious of which is: toolbars.
A toobar is an additional menu, embedded in the browser, that provides
easy access to an Internet service. Google's toolbar, for example,
helps block unwanted popup adverts.
Browsers support advanced features - usually hidden deeper within
the browser - like: accessing proxy
servers; controlling Internet content for children; and setting
privacy options. The primary features of a browser locate web content,
and the advanced features dictate how that content is accessed and
For browsers to run optimally, their cache
of data needs to be periodically deleted. There is a range of third
party software that automatically deletes: temporary Internet files;
saved passwords; cookies; recently
types URLs; history of accessed URLs; last download locations and
Browser Compatibility: Web Standards
An important aspect of web browsers is their compatibility with
web standards; web standards are recommended by the World Wide Web
Consortium. The World Wide Web Consortium (W3C), founded by Tim
Berners-Lee, the inventor of the World Wide Web: is an international
standards organisation for the World Wide Web. Webpages are designed
in HTML, the specification of which is managed by the W3C. W3C attempts
to enforce software vendors to adhere to their specification and
standards: so that webpages will be displayed identically by each
client program (browser).
While it is not essential - for users - that a webpage renders
identically in each web browser; it is important for web developers.
If a web developer designs a website that does not load correctly
in one browser: then the website may lose visitors and potential
customers. The most popular web browser - by usage share - has been
Microsoft's Internet Explorer, and some versions of this browser
are renowned for not compiling with W3C web standards; Internet
Explorer version 6.0 being a case in point.
A group of disgruntled web developers - frustrated by some browsers
ignoring web standards - formed the Web Standards Project (WaSP)
in 1998: the purpose of the group was "to fight" for the
compliance of web standards in browsers. The WaSP has developed
the Acid1, Acid2, Acid3
and Acid4 tests: these tests test how browsers comply with HTML
4, CSS 1, CSS 2, CSS 2.1, CSS 3, DOM, SVG, and EcmaScript. At present
(2014), the Acid4 test is still to be created; WaSP is defunct,
as of 2013, so it may never be created.
The first web browsers were designed exclusively for desktop and
laptop computers, and, until relatively recently (2014) this trend
has continued to be the status quo. However, from the year 2000
onwards, the technology of mobile phones - also referred to as cell
phones and smartphones - has advanced in 'leaps and bounds'. This
has resulted in mobile phones being capable of browsing the web,
and increasingly, are capable of accessing all of the services available
to traditional computers.
However, due to the screen size and technological limitations of
mobile phones, browsers designed for desktop computers are rarely
compatible with mobile devices. Therefore, a range of 'mobile browsers'
have been designed; designed exclusively for mobile devices: mobile
browsers render web content so that it can be displayed within the
limitations of a mobile screen. Due to the popularity of browsing
the World Wide Web with mobile phones: many websites have designed
their webpages so they will 'serve' a mobile version of the page
for mobile browsers. Websites that are compatible with mobile browsers
are referred to as: the mobile web.
Mobile browsers, and by extension mobile phones, typically connect
to the Internet by either: 1) cellular / mobile networks;
2) wireless networks (wifi etc). Traditional browsers use
HTTP (Hypertext Transfer Protocol) to retrieve webpages across the
Internet; while mobile browsers support standard HTTP, they can
also use the Wireless Application Protocol (WAP). Likewise, while
mobile browsers can render webpages in the standard HyperText Markup
Language (HTML), they usually utilise 'lightweight' webpages designed
for them in markup languages, like: Handheld Device Markup Language
(HDML); Wireless Markup Language (WML);
and Extensible Hypertext Markup Language (XHTML). The Mobile Web
Initiative (MWI) has been
created by the W3C to help develop these markup languages and expand
the amount of mobile devices that can access the web.
Mobile browsers typically fall into two categories: 1) default
browser installed by the mobile device manufacturer; 2) user
installed mobile browser. While some mobile devices allow users
to remove the default browser and install another browser, many
mobile devices only allow the use of the default browser. The following
is a collection of popular mobile browsers: Amazon Silk, Android,
BlackBerry, Blazer, Chrome, Firefox for Mobile, Internet Explorer
Mobile, Kindle Basic Web, Opera Mobile, Safari Mobile, Skyfire and
Popular Web Browsers
- Amaya - Amaya is an open
source software project hosted by W3C.
- Over 20 million users (2005), designed by Mozilla.
- Google Crome (read
more) - Browser which was released in 2008.
- Hot Java
- Hot Java offers a lot of flexibility and runs on many platforms.
- Internet Explorer
more) - Released by Microsoft.
- Lynx - Lynx is a text
browser that allows greater speed than graphical browsers.
- Opera - The most popular
alternative browser due to its speed and features.
Browsers for the Mac
- Safari - Is the Mac
OS X default web browser and loads pages quickly for Mac pcs.
Browsers for Linux
- Amaya - Amaya is an open
source software project hosted by W3C.
- Dillo - Is a small (less
than 400 Kb), Written in C and aims to be stable.