WebBuilding

Events and eras

Web 2.0

Summary

Web 2.0 is the name given to the wave of websites that grew after the dot-com crash, in which users wrote, uploaded, tagged and shared much of the content themselves through blogs, wikis, video sites and social networks, while feeds and APIs let sites exchange data. Darcy DiNucci used the term in Print magazine in 1999. It spread after the Web 2.0 Conference run by O'Reilly Media and MediaLive International in October 2004 and Tim O'Reilly's essay "What Is Web 2.0" of September 30, 2005. Critics, including web inventor Tim Berners-Lee, called it jargon.

Web Building Encyclopedia · Events and eras · Last reviewed October 22, 2026 · 12 min read

What Web 2.0 means

Web 2.0 is a name for the kind of website that spread across the World Wide Web in the middle of the 2000s. On these sites, visitors did more than read pages: they wrote posts, uploaded photos and videos, added tags and comments, and built much of the content themselves.

The “2.0” borrows the way software makers number a major new version, but the term never named a new protocol or file format. Tim O’Reilly, whose company did the most to spread it, wrote in 2005 that Web 2.0 “doesn’t have a hard boundary, but rather, a gravitational core”: a set of principles and practices that many sites shared to different degrees.1

O’Reilly explained the idea with pairs of older and newer services. Some of the pairs in his 2005 essay:1

“Web 1.0”“Web 2.0”
Britannica OnlineWikipedia
Personal websitesBlogging
OfotoFlickr
Content management systemsWikis
Directories (taxonomy)Tagging (“folksonomy”)
StickinessSyndication
PublishingParticipation

The label was disputed from the start. O’Reilly acknowledged that some people dismissed it as an empty marketing buzzword while others accepted it as the new conventional wisdom. He also noted that in the year and a half after the first conference, the term had gathered more than 9.5 million citations in Google.1

Where the term came from

Darcy DiNucci, 1999

The earliest well-documented use is by Darcy DiNucci, in an article titled “Fragmented Future” in Print, an American design magazine. A WorldCat catalog record lists it under the heading “Design & New Media” in Print 53 (1999), page 32, with the subtitle “Web development faces a process of mitosis, mutation, and natural selection.” The record gives no month.2

Her meaning was not the later one. She used the term about web design, arguing that the web was beginning to fragment across many kinds of devices and that designers would have to plan for each format’s screen size and resolution.3 A 2013 article in the Spanish news site elDiario.es summarized her prediction that the web would appear on phones, televisions, car dashboards and even microwave ovens.4 A 2013 conference paper on the term’s history quotes her line: “The first glimmerings of Web 2.0 are beginning to appear, and we are just starting to see how that embryo might develop.”3

Sources disagree on the month. elDiario.es says she wrote the article in January 1999, while the Web Design Museum dates it to April 1999.45 The same elDiario.es article notes that O’Reilly is usually remembered as the term’s inventor, even though it had been used before.4

O’Reilly, MediaLive and the 2004 conference

In his essay, O’Reilly traced the concept to a conference brainstorming session between O’Reilly Media, his publishing company, and MediaLive International, a conference organizer. The setting was the aftermath of the dot-com bubble, whose bursting in the fall of 2001, he wrote, marked a turning point for the web. Dale Dougherty, an O’Reilly vice president, argued that far from having crashed, the web was more important than ever.1

On May 3, 2004, John Battelle announced on his blog that he was working with O’Reilly and MediaLive on a conference for and about the internet industry, to run from October 5 to 7 at the Hotel Nikko in San Francisco, with attendance by invitation.6 When it closed, Linux.com listed speakers including Jeff Bezos, Marc Benioff, John Doerr, Mitch Kapor, Marc Andreessen, Mary Meeker, Lawrence Lessig and Jerry Yang, with Battelle as conference chair.7 O’Reilly later wrote that he and Battelle set out a preliminary list of principles in their opening talk, the first of which was the web as platform.1

The 2005 essay

O’Reilly published “What Is Web 2.0: Design Patterns and Business Models for the Next Generation of Software” on September 30, 2005.1 It closes by suggesting that readers test any company calling itself Web 2.0 against its list of principles, adding that excellence in one area may count for more than small steps in all seven.8

The ideas in O’Reilly’s essay

The essay is organized around seven principles. In O’Reilly’s words and examples, they were:

  • The web as platform. O’Reilly contrasted Netscape, which he said framed the web as platform in terms of the old software business, with Google, and argued that value had moved to services delivered over the web.1
  • Harnessing collective intelligence. The most successful sites grew stronger from what their users contributed. O’Reilly noted that Wikipedia was already among the top 100 websites.9
  • Data is the next “Intel Inside.” Companies would compete on control of unique data that is hard to recreate and gets richer as more people use it.108
  • End of the software release cycle. Software became a service that changed continuously, with new features slipstreamed in on a monthly, weekly or even daily basis, a pattern O’Reilly called the perpetual beta.11
  • Lightweight programming models. Simple interfaces won over complex ones. Amazon, which offered both, reported that 95% of the use of its web services went to the lightweight one.11
  • Software above the level of a single device. Web 2.0 was no longer limited to the personal computer.11
  • Rich user experiences. Web applications began to feel like desktop programs. O’Reilly wrote that this reached the mainstream with Gmail, quickly followed by Google Maps.8

The essay also summed up what it called the core competencies of Web 2.0 companies, among them services instead of packaged software, trusting users as co-developers and harnessing collective intelligence.8

The technique behind those rich interfaces had been named a few months earlier. On February 18, 2005, Jesse James Garrett of the design firm Adaptive Path called it Ajax, “shorthand for Asynchronous JavaScript + XML.” He listed its parts as XHTML and CSS for display, the Document Object Model for changing the page, XML and XSLT for data, XMLHttpRequest for fetching data in the background, and JavaScript to tie them together. His examples were Google Suggest and Google Maps.12 O’Reilly called Ajax a key part of Web 2.0 applications such as Flickr, 37signals’ Basecamp and Backpack, Gmail and Orkut.8

User-generated content

The feature most people associate with Web 2.0 is content made by users. A 2007 report by the Organisation for Economic Co-operation and Development (OECD) defined user-created content by three traits: it is made publicly available over the internet, it reflects a certain amount of creative effort, and it is created outside of professional routines and practices.13 The report noted that the work could be published in a limited setting, such as a social networking page open only to a select group of people, for example fellow university students.13

O’Reilly argued that such sites were designed so that they improved with use. In his account, users add value, and the services show network effects by the way they are built: each new contributor makes the site more useful to the next.10

Tagging was one example. Instead of filing pages in a fixed directory, users attached their own keywords. O’Reilly described this “folksonomy” as collaborative categorization using freely chosen keywords called tags.9 Thomas Vander Wal says he coined the word on July 24, 2004, on the mailing list of what is now the Information Architecture Institute, and defines it as the result of personal free tagging of anything with a URL for one’s own retrieval.14

Video sharing grew fast. YouTube was founded in February 2005, and on October 9, 2006, Google agreed to buy it for $1.65 billion in stock. Google’s announcement described it as a consumer media company for people to watch and share original videos worldwide through a web experience.15

At the end of 2006, Time magazine named “You” its Person of the Year, in its issue dated December 25, 2006. Its technology writer Lev Grossman said the honor was for “seizing the reins of the global media,” and an NBC News report on the choice pointed to blogs, YouTube and the social network MySpace as examples of the user-generated content behind it.16

Blogs and RSS

Blogs

O’Reilly called the rise of blogging one of the most highly touted features of the Web 2.0 era, and defined a blog at its simplest as a personal home page in diary format.10 What changed was the way blogs linked to each other. He described the permalink, a permanent address for each individual post, as the first and most successful attempt to build bridges between weblogs.10

Blogging software became free and easy to install. The first release of WordPress, announced by Matt Mullenweg on May 27, 2003, is one example.17 By 2006 blogging had a large audience. Telephone surveys by the Pew Research Center, run from November 2005 to April 2006, found that 8% of American internet users, about 12 million adults, kept a blog, and 39%, about 57 million, read them.18

RSS and Atom

RSS (Really Simple Syndication) is a family of XML formats for publishing a site’s updates. A reader subscribes to a site’s RSS document, called a feed, and the updates arrive in a feed reader without the reader having to check each site by hand.19 O’Reilly wrote that RSS lets someone link not just to a page but subscribe to it, and called it “the most significant advance in the fundamental architecture of the web.”10

The format began before the Web 2.0 label. The RSS Advisory Board, which keeps the format’s history, dates its versions this way:20

  • March 15, 1999: RSS 0.90, published by Netscape and written by Ramanathan Guha.
  • July 10, 1999: RSS 0.91 from Netscape, written by Dan Libby.
  • June 9, 2000: a UserLand version of RSS 0.91, written by Dave Winer.
  • August 19, 2002: RSS 2.0, published by UserLand.
  • July 15, 2003: RSS 2.0.1, published by the Berkman Center for Internet and Society at Harvard Law School and written by Dave Winer.

The Harvard copy of the specification describes RSS as a dialect of XML and offers it under a Creative Commons Attribution/Share Alike license.21 A rival feed format, Atom, became a standards-track document of the Internet Engineering Task Force as RFC 4287 in December 2005, edited by Mark Nottingham and Robert Sayre.22

Google’s own feed reader did not last. On March 13, 2013, Google said it would retire Google Reader on July 1, 2013, because usage had declined over the years.23 Feeds themselves did not go away, as the section on your website below explains.

APIs and web services

An API (application programming interface) is a set of features and rules inside a program that lets other software work with it, as opposed to an interface for a human user. MDN Web Docs describes it as a kind of contract between the application offering it and other software.24

O’Reilly’s essay argued that simple APIs beat complex ones. Large companies had built a complex stack of web services standards, he wrote, but the simpler approach won most of the use, as Amazon’s 95% figure showed.11 He urged designers to build for hackability and remixability.11

Google Maps showed how that worked in practice. Garrett had used it as one of his two examples of Ajax.12 O’Reilly wrote that the map’s simple Ajax interface was quickly decoded by outside programmers, who reused its data to build new services.11 On June 29, 2005, Google released an official Maps API so that people could put interactive, draggable, zoomable maps, with satellite imagery, on their own websites.25

Web 2.0 ideas soon reached phones. On June 11, 2007, before the first iPhone shipped, Apple said it would run third-party applications “created with Web 2.0 Internet standards” when it went on sale on June 29.26

Criticism and legacy

Tim Berners-Lee’s objection

The sharpest objection came from the web’s inventor. In a podcast interview with IBM developerWorks, excerpted by ReadWriteWeb on August 22, 2006, Tim Berners-Lee rejected the idea that the first web connected computers while Web 2.0 connected people. He said the web had been about connecting people from the start, and that Web 2.0 was “a piece of jargon, nobody even knows what it means.”27 He added that if Web 2.0 meant blogs and wikis, that was people talking to people, which was what the web was supposed to be all along, and that in practice Web 2.0 meant using the standards that people working on “Web 1.0” had already produced.27

His own first program supports the point. The first web browser, WorldWideWeb, was in his words a browser-editor, a program for writing pages as well as reading them, though it could save only local files because the server side of editing was not yet in place.28

Other critics

Paul Graham wrote in a November 2005 essay that he first heard the phrase as the name of the 2004 conference and that it was meaningless at first. He argued it had since come to mean three things: Ajax, which he summed up as JavaScript now working well enough for real applications; democracy, in which amateurs can surpass professionals; and not mistreating users.29

Others questioned the faith in amateurs. On October 3, 2005, Nicholas Carr argued in a blog post titled “The amorality of Web 2.0” that its promoters venerated the amateur and distrusted the professional, and he called Wikipedia unreliable at a factual level.30 Andrew Keen expanded the argument in his 2007 book The Cult of the Amateur: How Today’s Internet Is Killing Our Culture, which says that the line between trained experts and uninformed amateurs blurs when anyone can publish.31

The name itself caused a dispute. In a letter dated May 24, 2006, a lawyer for CMP, which ElectricNews.net described as an O’Reilly partner company, told IT@Cork, an Irish non-profit networking forum, that CMP had a pending application to register Web 2.0 as a service mark for conferences and trade shows, and objected to the group using the name for a conference the following month. Sara Winge, O’Reilly Media’s vice president of communications, apologized for how the matter had been handled, let the group use the name that year and said the company would protect the mark for conferences.32

Silos and the end of the conference

Some of the largest Web 2.0 sites became the subject of a new complaint. In the December 2010 issue of Scientific American, Berners-Lee wrote that large social-networking sites were walling off information their users posted from the rest of the web, naming Facebook, LinkedIn and Friendster. Each site, he wrote, had become a silo, walled off from the others.3334

The conference that spread the name began in 2004 and was known by 2012 as the Web 2.0 Summit. On April 4, 2012, TechCrunch reported that it would not be held that year: Battelle had put it on hiatus because he could not write a book and plan the program at the same time.35

The term has since become a label for an era, but its pieces remain in daily use: comment threads, tags, feeds, embedded maps and the APIs that connect one service to another.

Timeline

  1. Google announces it will retire Google Reader on July 1, 201323
  2. John Battelle puts the Web 2.0 Summit on hiatus after the 2011 event35
  3. Tim Berners-Lee warns in Scientific American that social sites are walled-off silos33
  4. Apple says the iPhone will run third-party apps built with Web 2.0 standards26
  5. Time names "You" its Person of the Year for 200616
  6. Google agrees to buy YouTube for $1.65 billion in stock15
  7. Tim Berners-Lee calls Web 2.0 a piece of jargon27
  8. A dispute over the "Web 2.0" service mark and IT@Cork becomes public32
  9. Tim O'Reilly publishes "What Is Web 2.0"1
  10. Google releases the Google Maps API for use on other websites25
  11. Jesse James Garrett names Ajax12
  12. The first Web 2.0 Conference opens at the Hotel Nikko, San Francisco6
  13. UserLand publishes RSS 2.020
  14. Netscape publishes RSS 0.9020
  15. Darcy DiNucci uses the term Web 2.0 in Print magazine2

What it means for your website

The label is old, but its pieces are on many small-business sites: feeds, comments, reviews, embedded maps and APIs. Each one comes with a small job for the site owner.

  • Your feed already exists. WordPress produces RSS 2.0, Atom and older RSS feeds by default, plus a feed of comments.36 Feed readers and other tools can pick up new posts from it, so keep post titles and excerpts clear, and check the feed after a website migration.
  • Moderate what visitors post. WordPress can hold any comment for approval, and can hold comments with many links, a common sign of spam, for manual review.37 If comments add nothing to your business, you can switch them off.
  • Keep reviews honest. A Federal Trade Commission rule announced on August 14, 2024 bans businesses from creating or buying fake reviews, from paying for reviews that must be positive or negative, and from using groundless legal threats or intimidation to get negative reviews removed.38 Our guide to website laws in the US covers the other rules that apply.
  • Own the keys to embedded services. Google Maps Platform requires an API key for authentication and billing.39 Create it under a Google account your business controls, not a former designer’s, so the map does not break when someone leaves.
  • Ask what your platform exposes. WordPress’s REST API lets other applications read and write your site’s content as JSON.40 Before you connect an outside app, check which account it signs in with and what it is allowed to change.

We build on WordPress every week, and these settings are part of every launch. Our WordPress review and the websites and social media guide explain where your site fits next to the platforms that grew out of the Web 2.0 years.

See also

References

  1. What Is Web 2.0: Design Patterns and Business Models for the Next Generation of Software. Tim O'Reilly, O'Reilly Media. 2005-09-30. accessed October 22, 2026.
  2. DESIGN & NEW MEDIA: Fragmented Future (Darcy DiNucci), Print, vol. 53, 1999, p. 32 (catalog record). WorldCat, OCLC. 1999. accessed October 22, 2026.
  3. Web 2.0: the origin of the word that has changed the way we understand public relations. Cristina Aced Toledano, Barcelona International PR Conference (via ResearchGate). 2013-07. accessed October 22, 2026.
  4. El origen del concepto Web 2.0 y su maltrato. Pablo G. Bejerano, elDiario.es. 2013-04-12. accessed October 22, 2026.
  5. Web 2.0 (1999). Web Design Museum. accessed October 22, 2026.
  6. Web 2.0: The Conference. John Battelle, John Battelle's Search Blog. 2004-05-03. accessed October 22, 2026.
  7. Web 2.0: Possibly the best IT business conference of 2004. Chris Preimesberger, Linux.com. 2004-10-08. accessed October 22, 2026.
  8. What Is Web 2.0, page 5: Rich user experiences and core competencies. Tim O'Reilly, O'Reilly Media. 2005-09-30. accessed October 22, 2026.
  9. What Is Web 2.0, page 2: Harnessing collective intelligence. Tim O'Reilly, O'Reilly Media. 2005-09-30. accessed October 22, 2026.
  10. What Is Web 2.0, page 3: Blogging and the wisdom of crowds. Tim O'Reilly, O'Reilly Media. 2005-09-30. accessed October 22, 2026.
  11. What Is Web 2.0, page 4: End of the software release cycle and lightweight programming models. Tim O'Reilly, O'Reilly Media. 2005-09-30. accessed October 22, 2026.
  12. Ajax: A New Approach to Web Applications. Jesse James Garrett, Adaptive Path (print copy of the essay, hosted by MIT). 2005-02-18. accessed October 22, 2026.
  13. Participative Web: User-Created Content (DSTI/ICCP/IE(2006)7/FINAL). OECD Directorate for Science, Technology and Industry, Committee for Information, Computer and Communications Policy. 2007-04-12. accessed October 22, 2026.
  14. Folksonomy Coinage and Definition. Thomas Vander Wal, vanderwal.net. accessed October 22, 2026.
  15. Google To Acquire YouTube for $1.65 Billion in Stock. Google Press Center. 2006-10-09. accessed October 22, 2026.
  16. Time magazine's 'Person of the Year' is … You. NBC News. 2006-12. accessed October 22, 2026.
  17. WordPress Now Available. Matt Mullenweg, WordPress.org News. 2003-05-27. accessed October 22, 2026.
  18. Bloggers: A portrait of the internet's new storytellers. Amanda Lenhart and Susannah Fox, Pew Research Center. 2006-07-19. accessed October 22, 2026.
  19. RSS (glossary). MDN Web Docs, Mozilla. accessed October 22, 2026.
  20. RSS History. RSS Advisory Board. accessed October 22, 2026.
  21. RSS 2.0 Specification. Berkman Center for Internet & Society, Harvard Law School. 2003-07-15. accessed October 22, 2026.
  22. RFC 4287: The Atom Syndication Format. Mark Nottingham and Robert Sayre (editors), IETF, RFC Editor. 2005-12. accessed October 22, 2026.
  23. A second spring of cleaning. Urs Hölzle, Official Google Blog. 2013-03-13. accessed October 22, 2026.
  24. API (glossary). MDN Web Docs, Mozilla. accessed October 22, 2026.
  25. Google Releases Maps API for External Use. Google Developers Blog. 2005-06-29. accessed October 22, 2026.
  26. iPhone to Support Third-Party Web 2.0 Applications. Apple Newsroom. 2007-06-11. accessed October 22, 2026.
  27. Tim Berners-Lee Disses Web 2.0 (excerpt of an IBM developerWorks podcast). Richard MacManus, ReadWriteWeb (ReadWrite). 2006-08-22. accessed October 22, 2026.
  28. The WorldWideWeb browser. Tim Berners-Lee, W3C. accessed October 22, 2026.
  29. Web 2.0. Paul Graham, paulgraham.com. 2005-11. accessed October 22, 2026.
  30. The amorality of Web 2.0. Nicholas Carr, Rough Type. 2005-10-03. accessed October 22, 2026.
  31. The Cult of the Amateur: How Today's Internet Is Killing Our Culture (catalog record). Andrew Keen, Doubleday/Currency, New York, 2007 (WIPO Library record). 2007. accessed October 22, 2026.
  32. O'Reilly Media and IT@Cork in 'Web 2.0' trademark battle. Maxim Kelly, ElectricNews.net, via The Register. 2006-05-26. accessed October 22, 2026.
  33. Long Live the Web: A Call for Continued Open Standards and Neutrality. Tim Berners-Lee, Scientific American, vol. 303, no. 6. 2010-12. accessed October 22, 2026.
  34. Berners-Lee: Facebook 'threatens' web future. Cade Metz, The Register. 2010-11-20. accessed October 22, 2026.
  35. The Web 2.0 Summit, Tim O'Reilly and John Battelle's Tech-Palooza, Is On Indefinite "Hiatus". Colleen Taylor, TechCrunch. 2012-04-04. accessed October 22, 2026.
  36. WordPress Feeds. Advanced Administration Handbook, WordPress.org. accessed October 22, 2026.
  37. Comment Moderation. WordPress Documentation, WordPress.org. accessed October 22, 2026.
  38. Federal Trade Commission Announces Final Rule Banning Fake Reviews and Testimonials. Federal Trade Commission. 2024-08-14. accessed October 22, 2026.
  39. Set up the Maps JavaScript API: Get an API key. Google Maps Platform documentation, Google for Developers. accessed October 22, 2026.
  40. REST API Handbook. WordPress Developer Resources, WordPress.org. accessed October 22, 2026.

Web Building Encyclopedia. First published October 22, 2026. Last reviewed October 22, 2026. Every fact on this page is linked to a source we opened. Spotted an error? Write to [email protected].