The World Wide Web

Required Reading for this lecture:

  1. WWW: Past, Present, and Future by Tim Berners-Lee from 1996.


Tim Berners-Lee, Hypertext, and the birth of the WWW

The World Wide Web is the brainchild of Tim Berners-Lee. The following chronology is taken from the online article: A Little History of the World Wide Web at the [ World Wide Web Consortium] website. During the last five years of the millenium, the WWW expanded rapidly into the mainstream. Some of the major developments are Research into the infrastructure of the WWW has continued (see the W3C list of talks for an overview of how the infrastructure has developed).


The World Wide Web as a Concept

In a 1992 seminar ( archived here) Tim Berners-Lee, the primary force behind the creation of the World Wide Web, described the World Wide Web as a "distributed heterogeneous collaborative multimedia information system." This string of buzzwords is a fairly accurate reflection of the current state of the web. Lets examine the jargon one word at a time: More recently the web has become a communication system (with internet telephony), a broadcast system (with so called internet multicasting), and a computing system (with Java as the main computing engine). Berners-Lee conceived of the World Wide Web as being a general information system with the following properties.
  1. Universal Readership -- information on the web should be accessible to anyone on any computer anywhere in the world, and everyone should be able to use the same browser to access that information
  2. Hypertext -- the information should be organized by placing hyperlinks in each page allowing the user to visit related pages just by clicking on the appropriate link.
  3. Searching -- users should also be able to find information by using search engines that generate a list of pages meeting some user-given criteria.
  4. Client-Server Model -- any one on the internet should be able to create web pages as well as read web pages. All users become publishers.
  5. Format Negotation -- the format of the information stored on the web is free to evolve and browsers and servers will first agree on the format of the data to be exchanged before actually sending the data.


Web Services today

Many types of web services are offered today. These include the following:


The WWW as a meta-computer

With the advent of Java and other client-side computing paradigms, the WWW can be viewed as a single, extremely large computer system.

References:

  1. CERN Information Management proposal of 1989
  2. WWW: An Illustrated Seminar by Tim Berners Lee from 1992.
  3. W3 Concepts from the 1992 online seminar by Berners-Lee.
  4. A Little History of the World Wide Web
  5. World Wide Web Consortium
  6. "As We May Think" by Vannevar Bush, published in The Atlantic Monthly, July 1945. See especially, Section 8 where he describes a future which has, for the most part, become realized by the WWW.
  7. WWW Beyond the Basics -- an online book written by a graduate level CS class at Virginia Tech in 1996
This lecture is largely based on materials taken from the web site of the World Wide Web Consortium