In Italy we celebrate the 20th anniversary of the web. Internet was born Berners-Lee is a computer scientist, in particular expert in text editors, real-time software and communications. He is considered the most influencal scientists alive today, and he started to work on hypertextual systems in 1980 developing Enquire, and in 1989 he started the World-Wide Iniziative. Robert Caillau joined it in 1990 and in the next year arrived also Jean-François Groff and Bernd Pollerman. The team laid the basis of the modern web with three papers: World-Wide Web: The information universe(6), World-Wide Web: An information infrastructure for high-energy physics(7), World-Wide Web(8).
In the first paper, published in a referred journal, the researchers begin in The Dream section with the following words:
Pick up your pen, mouse, or favorite pointing device and press it on a reference in this document perhaps to the author's name, or organization, or some related work. Suppose you are then directly presented with the background material other papers, the author's coordinates, the organization's address, and its entire telephone directory. Suppose each of these documents has the same property of being linked to other original documents all over the world. You would have at your fingertips all you need to know about electronic publishing, highenergy physics, or for that matter, Asian culture. If you are reading this article on paper, you can only dream, but read on.The construction of Berners-Lee's group dream start in 1945 with the historical paper of Vannevar Bush, As we may think(1) where the american inventor laid the basis to construct a scientists' network through hypertexts. The way towards this system had another founding father, Douglas Engelbart(2). He is also an american inventor, with scandinavian origin, pioneer in the development of graphical user interfaces. And after Bush and Engelbart we arrive to Berners-Lee, Caillau and collegues.
The structure developed by Berners-Lee team is outlined by the following diagram:

- Indexes are documents, and so may themselves be found by searches and/or following links. An index is represented to the user by a "cover page" that describes the data indexed and the properties of the search engine.
- The documents in the web do not have to exist as files; they can be "virtual" documents generated by a server in response to a query or document name. They can therefore represent views of databases, or snapshots of changing data (such as the weather forecasts, financial information, etc.).
- a common naming scheme for documents
- common network access protocols
- common data formats for hypertext
