The World Wide Web ("WWW", "W3" or simply "the Web") is a global information medium that users can access via computers connected to the Internet. The term is often used as a synonym for the Internet, but the Web is a service that operates over the Internet, just as email and videoconferencing do. The history of the Internet and the history of hypertext date back significantly further than that of the World Wide Web.

Tim Berners-Lee invented the World Wide Web while working at CERN in 1989. He proposed a "universal linked information system" using several concepts and technologies, the most fundamental of which was the connections that existed between information. He developed the first web server, the first web browser, and a document formatting protocol, called Hypertext Markup Language (HTML). After publishing the markup language in 1991, and releasing the browser source code for public use in 1993, many other web browsers were soon developed, with Marc Andreessen's Mosaic (later Netscape Navigator) being particularly easy to use and install, and often credited with sparking the Internet boom of the 1990s. It was a graphical browser which ran on several popular office and home computers, bringing multimedia content to non-technical users by including images and text on the same page.

Websites for use by the general public began to emerge in 1993–94. This spurred competition in server and browser software, highlighted in the Browser wars which was initially dominated by Netscape Navigator and Internet Explorer. Following the complete removal of commercial restrictions on Internet use by 1995, commercialization of the Web amidst macroeconomic factors led to the dot-com boom and bust in the late 1990s and early 2000s.

The features of HTML evolved over time, leading to HTML version 2 in 1995, HTML3 and HTML4 in 1997, and HTML5 in 2014. The language was extended with advanced formatting in Cascading Style Sheets (CSS) and with programming capability by JavaScript. AJAX programming delivered dynamic content to users, which sparked a new era in Web design, styled Web 2.0. The use of social media, becoming commonplace in the 2010s, allowed users to compose multimedia content without programming skills, making the Web ubiquitous in everyday life.

Background

Precursors The underlying concept of hypertext as a user interface paradigm originated in projects in the 1960s, from research such as the Hypertext Editing System (HES) by Andries van Dam at Brown University, IBM Generalized Markup Language, Ted Nelson's Project Xanadu, and Douglas Engelbart's oN-Line System (NLS). Both Nelson and Engelbart were in turn inspired by Vannevar Bush's microfilm-based memex, which was described in the 1945 essay "As We May Think". Other precursors were FRESS and Intermedia. Paul Otlet's project Mundaneum has also been named as an early 20th-century precursor of the Web.

ENQUIRE In 1980, Tim Berners-Lee, at the European Organization for Nuclear Research (CERN) in Switzerland, built ENQUIRE, as a personal database of people and software models, but also as a way to experiment with hypertext; each new page of information in ENQUIRE had to be linked to another page. When Berners-Lee built ENQUIRE, the ideas developed by Bush, Engelbart, and Nelson did not influence his work, since he was not aware of them. However, as Berners-Lee began to refine his ideas, the work of these predecessors would later help to confirm the legitimacy of his concept.

During the 1980s, many packet-switched data networks emerged based on various communication protocols (see Protocol Wars). One of these standards was the Internet protocol suite, which is often referred to as TCP/IP. As the Internet grew through the 1980s, many people realized the increasing need to be able to find and organize files and use information. By 1985, the Domain Name System (upon which the Uniform Resource Locator is built) came into being. Many small, self-contained hypertext systems were created, such as Apple Computer's HyperCard (1987).

Return to CERN Berners-Lee's contract in 1980 was from June to December, but in 1984 he returned to CERN in a permanent role, and considered its problems of information management: physicists from around the world needed to share data, yet they lacked common machines and any shared presentation software. Shortly after Berners-Lee's return to CERN, TCP/IP protocols were installed on Unix machines at the institution, turning it into the largest Internet site in Europe. In 1988, the first direct IP connection between Europe and North America was established and Berners-Lee began to openly discuss the possibility of a web-like system at CERN. He was inspired by a book, Enquire Within upon Everything. Many online services existed before the creation of the World Wide Web, such as CompuServe, Usenet, Internet Relay Chat, Telnet and bulletin board systems. Before the internet, UUCP was used for online services such as e-mail, and BITNET was also another popular network.

1989–1991: Origins CERN

While working at CERN, Tim Berners-Lee became frustrated with the inefficiencies and difficulties posed by finding information stored on different computers. On 12 March 1989, he submitted a memorandum, titled "Information Management: A Proposal", to the management at CERN. (At the beginning of chapter 12 of his 2025 book, Berners-Lee confides that "the first document reads only 'March 1989'" — that he gave "12 March — which is actually my mother's birthday.") The proposal used the term "web" and was based on "a large hypertext database with typed links". It described a system called "Mesh" that referenced ENQUIRE, the database and software project he had built in 1980, with a more elaborate information management system based on links embedded as text: "Imagine, then, the references in this document all being associated with the network address of the thing to which they referred, so that while reading this document, you could skip to them with a click of the mouse." Such a system, he explained, could be referred to using one of the existing meanings of the word hypertext, a term that he says was coined in the 1950s. Berners-Lee notes the possibility of multimedia documents that include graphics, speech and video, which he terms hypermedia.

Although the proposal attracted little interest, Berners-Lee was encouraged by his manager, Mike Sendall, to begin implementing his system on a newly acquired NeXT workstation. He considered several names, including Information Mesh, The Information Mine or Mine of Information, but settled on World Wide Web. Berners-Lee found an enthusiastic supporter in his colleague and fellow hypertext enthusiast Robert Cailliau who began to promote the proposed system throughout CERN. Berners-Lee and Cailliau pitched Berners-Lee's ideas to the European Conference on Hypertext Technology in September 1990, but found no vendors who could appreciate his vision.

Berners-Lee's breakthrough was to marry hypertext to the Internet. In his book Weaving The Web, he explains that he had repeatedly suggested to members of both technical communities that a marriage between the two technologies was possible. But, when no one took up his invitation, he finally assumed the project himself. In the process, he developed three essential technologies: a system of globally unique identifiers for resources on the Web and elsewhere, the universal document identifier (UDI), later known as uniform resource locator (URL); the publishing language Hypertext Markup Language (HTML); the Hypertext Transfer Protocol (HTTP).

With help from Cailliau he published a more formal proposal on 12 November 1990 to build a "hypertext project" called WorldWideWeb (abbreviated "W3") as a "web" of "hypertext documents" to be viewed by "browsers" using a client–server architecture.He Created the Web. Now He’s Out to Remake the Digital World , New York Times, by Steve Lohr, 10 January 2021. The proposal was modelled after the Standard Generalized Markup Language (SGML) reader Dynatext by Electronic Book Technology, a spin-off from the Institute for Research in Information and Scholarship at Brown University. The Dynatext system, licensed by CERN, was considered too expensive and had an inappropriate licensing policy for use in the general high energy physics community, namely a fee for each document and each document alteration.

At this point HTML and HTTP had already been in development for about two months and the first web server was about a month from completing its first successful test. Berners-Lee's proposal estimated that a read-only Web would be developed within three months and that it would take six months to achieve "the creation of new links and new material by readers, [so that] authorship becomes universal" as well as "the automatic notification of a reader when new material of interest to him/her has become available".

By December 1990, Berners-Lee and his work team had built all the tools necessary for a working Web: the HyperText Transfer Protocol (HTTP), the HyperText Markup Language (HTML), the first web browser (named WorldWideWeb, which was also a web editor), the first web server (later known as CERN httpd) and the first web site (https://info.cern.ch/) containing the first web pages that described the project itself was published on 20 December 1990. The browser could access Usenet newsgroups and FTP files as well. A NeXT Computer was used by Berners-Lee as the web server and also to write the web browser.

Working with Berners-Lee at CERN, Nicola Pellow developed the first cross-platform web browser, the Line Mode Browser.

1991–1994: The Web goes public, early growth

Initial launch In January 1991, the first web servers outside CERN were switched on. On 6 August 1991, Berners-Lee published a short summary of the World Wide Web project on the newsgroup alt.hypertext, inviting collaborators.

Paul Kunz from the Stanford Linear Accelerator Center (SLAC) visited CERN in September 1991, and was captivated by the Web. He brought the NeXT software back to SLAC, where librarian Louise Addis adapted it for the VM/CMS operating system on the IBM mainframe as a way to host the SPIRES-HEP database and display SLAC's catalog of online documents.Beyond direct network connections, early site-to-site archival transfers for VAX/VMS environments in late 1991 also utilized physical media distributions, such as PRIAM-formatted tapes, to seed the World Wide Web software across academic nodes like UCLA's Boelter Hall This was the first web server outside of Europe and the first in North America.

The World Wide Web had several differences from other hypertext systems available at the time. The Web required only unidirectional links rather than bidirectional ones, making it possible for someone to link to another resource without action by the owner of that resource. It also significantly reduced the difficulty of implementing web servers and browsers (in comparison to earlier systems), but in turn, presented the chronic problem of link rot.

Early browsers