Networking and Internetworking - Guide to Cloud Computing for Business and Technology Managers - page 34

tightly structuring information in outline formats. Nelson wanted some-
thing closer to Vannevar Bush's earlier concept, which Bush hoped would
replicate the mind's ability to make associations across subject boundaries.
Nelson worked tirelessly through the 1970s and 1980s to bring Xanadu to
life. He remained close to but always outside of the academic and research
community, and his ideas inspired the work at Brown University, led by
Andries van Dam. Independently of these researchers, Apple introduced
a program called HyperCard for the Macintosh in 1987. HyperCard imple-
mented only a fraction of the concepts of hypertext as understood by van
Dam or Nelson, but it was simple, easy to use, and even easy for a novice to
program. For all its limits, HyperCard brought the notion of nonlinear text
and graphics out of the laboratory setting.
Tim Berners-Lee would later use hypertext as part of the development of
the WWW.
2 .1 A R PA N E T
In the 1960s, there were approximately 10,000 computers in the world. These
computers were very expensive ($100K-$200K) and had very primitive pro-
cessing power. They contained only a few thousand words of magnetic
memory, and programming and debugging of these computers was diffi-
cult. Further, communication between computers was virtually nonexistent.
However, several computer scientists had dreams of worldwide networks of
computers, where every computer around the globe is interconnected to all
of the other computers in the world. For example, Licklider wrote memos
in the early 1960s on his concept of an intergalactic network. This concept
envisaged that everyone around the globe would be interconnected and able
to access programs and data at any site from anywhere.
The US Department of Defense founded the Advance Research Projects
Agency (ARPA) in the late 1950s. ARPA embraced high-risk, high-return
research and laid the foundation for what became ARPANET and later the
Internet. J.C.R. Licklider was an early pioneer of AI, and he also formu-
lated the idea of a global computer network. He wrote his influential paper,
“ Man-Computer Symbiosis” in 1960, and this paper outlined the need for
simple interaction between users and computers. Licklider became the first
head of the computer research program at ARPA, which was called the
Information Processing Techniques Office (IPTO). He developed close links
with MIT, UCLA, and BBN Technologies and started work on his vision.
BBN Technologies (originally Bolt, Beranek, and Newman) was a high-
technology research and development company. It was especially famous
for its work in the development of packet switching for the ARPANET
and the Internet. It also did defense work for Defense Advanced Research