History of the Internet

The earliest idea of a computer network intended to allow general
communication between users of various computers was the ARPANET, the
world's first packet switching network, which first went online in 1969.

The Internet's roots lie within the ARPANET, which not only was the
intellectual forerunner of the Internet, but was also initially the core
network in the collection of networks in the Internet, as well as a
important tool in developing the Internet (being used for communication
between the groups working on internetworking research).

Motivation for the Internet

The need for an internetwork appeared with ARPA's sponsorship, by Robert
Kahn, of the development of a number of innovative networking technologies;
in particular, the first packet radio networks (inspired by the ALOHA
network), and a satellite packet communication program. Later, local area
networks (LAN's) would also join the mix.

Connecting these disparate networking technologies was not possible with the
kind of protocols used on the ARPANET, which depended on the exact nature of
the subnetwork. A wholly new kind of networking architecture was needed.

Early Internet Work

Kahn recruited Vinton Cerf to work with him on the problem, and they soon
worked out a fundamental reformulation, where instead of the network being
responsible for reliability, as in the ARPANET, the hosts became
responsible. Cerf credits Herbert Zimmerman and Louis Pouzin (designer of
the CYCLADES network) with important influences on this design.

With the role of the network reduced to the bare minimum, it because
possible to join together almost any networks, no matter what their
characteristics, thereby solving Kahn's initial problem. (One popular saying
has it that TCP/IP, the eventual product of Cerf and Kahn's work, will run
over "two tin cans and a string".) A computer called a gateway (a name later
changed to router to avoid confusion with a number of other kinds of
devices, also called gateways) is provided with an interface to each
network, and fowards packets back and forth between them.

Happily, this new concept was a perfect fit with the newly emerging local
area networks, which were revolutionizing communication between computers
within a site.

Growth

The early Internet, based around the ARPANET, was government-funded and
therefore restricted to research use only. Commercial use was strictly
forbidden. This initially restricted connections to military sites and
universities. During the 1980s, as the TCP/IP protocols (developed by Vint
Cerf and others) replaced earlier protocols like NCP, the connections
expanded to more colleges and even to a growing number of companies such as
Digital Equipment Corporation and Hewlett-Packard who were participating in
research projects.

Regional TCP/IP-based networks such as NYSERNet (New York State Education
and Research Network) and BARRNet (Bay Area Regional Research Network) grew
up and started interconnecting with the ARPANET. This greatly expanded the
reach of the growing network, and to a great extent was the point where the
ARPANET turned into the Internet.

At the end of the 1980s, the US Department of Defense decided the network
was developed enough for its initial purposes, and decided to stop further
funding. The US National Science Foundation, another branch of the US
government, took over responsibility for the core Internet backbone. In 1989
the NSFNet backbone was established, the US military broke off as a separate
MILNET network, and the ARPANET was shut down.

Commercialization and Privatization

Parallel to the ARPANET, other networks were growing. Some were educational
and centrally-organized like BITNET and CSNET. Others were a grass-roots mix
of school, commercial, and hobby like the UUCP network.

During the late 1980s the first Internet Service Provider companies were
formed. Companies like PSINet, UUNet, Netcom, and Portal were formed to
provide service to the regional research networks and provide alternate
network access (like UUCP-based email and Usenet News) to the public.

The interest in commercial use of the Internet became a hotly-debated topic.
Although commercial use was forbidden, the exact definition of commercial
use could be unclear and subjective. Everyone agreed that one company
sending an invoice to another company was clearly commercial use, but
anything less was up for debate. The alternate networks, like UUCP, had no
such restrictions, so many people were skirting grey areas in the
interconnection of the various networks.

Many university users were outraged at the idea of non-educational use of
their networks. Ironically it was the commercial Internet service providers
who brought prices low enough that junior colleges and other schools could
afford to participate in the new arenas of education and research.

By 1994, the NSFNet lost its standing as the backbone of the Internet. Other
competing commercial providers created their own backbones and
interconnections. Regional NAPs (network access points) became the primary
interconnections between the many networks. The NSFNet was dropped as the
main backbone, and commercial restrictions were gone.

Early applications

E-mail had existed as a message exchanging service on early time sharing
mainframe computers connected to a number of terminals. In 1971, Ray
Tomlinson developed the first system of exchanging addressed messages
between different, networked computers; he also introduced the
"name@computer" notation that is still used today. E-mail turned into the
internet "killer application" of the 1980s.

The second most popular application of the early internet was usenet, a
system of distributed discussion groups which is still going strong today.
Usenet had existed even before the internet, as an application of Unix
computers connected by telephone lines via the UUCP protocol.

It wasn't until the early to mid 1980s that the services we now use most on
the Internet started appearing. The concept of "domain names" (like
"wikipedia.org") requiring "Domain Name Servers" wasn't even introduced
until 1984. Before that all the computers were just addressed by their IP
addresses (numbers) or used a central "hosts" file maintained by the NIC.
Most protocols used for email and other services were significantly enhanced
after this.

Standards and Control

The Internet has developed a significant subculture dedicated to the idea
that the Internet is not owned or controlled by any one person, company,
group, or organization. Nevertheless, some standardization and control is
necessary for anything to function.

Many people wanted to put their ideas into the standards for communication
between the computers that made up this network, so a system was devised for
putting forward ideas. Basically you wrote your ideas in a paper called a
"Request for Comments" (RFC for short), and let everyone else read it.
People commented on and improved your ideas in new RFCs. (With its basis as
an educational research project, much of the documentation was written by
students or others who played significant roles in developing the network
but did not have official responsibility for defining standards. Thus the
very low-key name of "Request for Comments" rather than something like
"Declaration of Official Standard".) The first RFC (RFC1) was written on
April 7th, 1969. There are now well over 2000 RFCs, describing every aspect
of how the internet functions.

The Internet standards process has been as innovative as the Internet
itself. Prior to the Internet, standardization was a slow process run by
committees with arguing vendor-driven factions and lengthy delays. In
networking in particular, the results were monstrous patchworks of bloated
specifications.

The fundamental requirement for a networking protocol to become an Internet
standard is the existence of at least two working implementations that
interoperate with each other. This makes sense looking back, but it was a
new concept at the time. Other efforts built huge specifications with many
optional parts and then expected people to go off and implement them, and
only later did people find that they did not interoperate, or worse, the
standard was not even implementable.

In the 1980s, the International Organization for Standardization (ISO)
documented a new effort in networking called Open Systems Interconnect or
OSI. Prior to OSI, networking was completely vendor-developed and
proprietary. OSI was a new industry effort, attempting to get everyone to
agree to common network standards to provide multi-vendor interoperability.
The OSI model was the most important advance in teaching network concepts.
However, the OSI protocols or "stack" that were specified as part of the
project were a bloated mess. Standards like X.400 for e-mail took up several
large books, while Internet e-mail took only a few dozen pages at most in
RFC-822 and 823. Most protocols and specifications in the OSI stack are
long-gone today, such as token-bus media, CLNP packet delivery, FTAM file
transfer, and X.400 e-mail. Only one, X.500 directory service, still
survives with significant usage, mainly because the original unwieldy
protocol has been stripped away and effectively replaced with LDAP.

Some formal organization is necessary to make things operate. The first
central authority was the NIC (Network Information Center) at SRI (Stanford
Research Institute in Menlo Park, California).

   * InterNIC
   * IETF, IANA
   * ICANN

World Wide Web

The part of the Internet most people are probably most familiar with is the
World Wide Web.

As the Internet grew through the 1980s and early 1990s, many people realized
the growing need to be able to find and organize files and related
information. Projects such as Gopher, WAIS, and the Anonymous FTP Archive
Site list attempted to create schemes to organize distributed data and
present it to people in an easy-to-use form. Unfortunately, these projects
fell short in being able to accommodate all the various existing file and
data types, and in being able to grow without centralized bottlenecks.

One of the most promising ideas was hypertext, originated by Ted Nelson in
his Project Xanadu. Small self-contained hypertext systems had been created
before, such as Apple Computer's HyperCard, but nobody had figured out how
to scale it up to be able to refer to another document anywhere in the
world.

The solution was invented by Tim Berners-Lee in 1989. He was a physicist
working at CERN, the European Particle Physics Laboratory, and wanted a way
for physicists to share information about their research. His documentation
project was the source of the two key inventions that made the World Wide
Web possible.

The two key inventions were the uniform resource locator (URL) and hypertext
markup language (HTML). The URL was a simple way to specify the location of
a document anywhere on the Internet in one simple address that specified a
machine domain name, a path on that machine, and a protocol to use. HTML was
an easy way to embed codes into a text file that could define the structure
of a document and also include links pointing to other URLs. An additional
network protocol (HTTP: hypertext transfer protocol) was also invented for
reduced overhead in transfers, but the true genius of the new system was
that a new protocol was useful but not necessary; the URL and HTML system
was backwards compatible with existing protocols like FTP and Gopher.

Later around 1992 people realized that the simple markup capabilities of
HTML could allow graphics to be included in text documents. The first
graphical web browsers were developed, Viola and Mosaic. Mosaic was
developed by a team at the National Center for Supercomputing Applications
at the University of Illinois at Urbana-Champaign (NCSA-UIUC), led by Marc
Andreesen. Andreesen left NCSA-UIUC and joined Jim Clark, one of the
founders of SGI (Silicon Graphics, Inc.). They started Mosaic Communications
which became Netscape Communications Corporation , making Netscape Navigator
the first commercially successful browser. Microsoft acquired technology
from SpyGlass (who got their technology from NCSA) to develop Internet Explorer.

The ease of creating new Web documents and linking to existing ones caused
exponential growth. As the Web grew, search engines were created to track
pages on the web and allow people to find things. The first search engine,
Lycos, was created in 1993 as a university project. In 1993, the first web
magazine, The Virtual Journal, was published by a University of Maine
student. At the end of 1993, Lycos indexed a total of 800,000 web pages.

By August 2001, the Google search engine tracked over 1.3 billion web pages
and the growth continues. At the end of 2002, Google's index exceeded 3
billion pages.