Web 2.0

Knowledge Base

Web 2.0 describes World Wide Web sites that use technology beyond the static pages of earlier Web sites. The term was coined in 1999 by Darcy DiNucci and was popularized by Tim O’Reilly at the O’Reilly Media Web 2.0 conference in late 2004. Although Web 2.0 suggests a new version of the World Wide Web, it does not refer to an update to any technical specification, but rather to cumulative changes in the way Web pages are made and used.

A Web 2.0 site may allow users to interact and collaborate with each other in a social media dialogue as creators of user-generated content in a virtual community, in contrast to Web sites where people are limited to the passive viewing of content. Examples of Web 2.0 include social networking sites, blogs, wikis, folksonomies, video sharing sites, hosted services, Web applications, and mashups.

Whether Web 2.0 is substantively different from prior Web technologies has been challenged by World Wide Web inventor Sir Tim Berners-Lee, who describes the term as jargon. His original vision of the Web was “a collaborative medium, a place where we [could] all meet and read and write”.


The term “Web 2.0” was first used in January 1999 by Darcy DiNucci, a consultant on electronic information design (information architecture). In her article, “Fragmented Future”, DiNucci writes:

The Web we know now, which loads into a browser window in essentially static screenfuls, is only an embryo of the Web to come. The first glimmerings of Web 2.0 are beginning to appear, and we are just starting to see how that embryo might develop. The Web will be understood not as screenfuls of text and graphics but as a transport mechanism, the ether through which interactivity happens. It will […] appear on your computer screen, […] on your TV set […] your car dashboard […] your cell phone […] hand-held game machines […] maybe even your microwave oven.

Writing when Palm Inc. was introducing its first Web-capable personal digital assistant, supporting Web access with WAP, DiNucci saw the Web “fragmenting” into a future that extended far beyond the browser/PC combination it was identified with. Her vision of the Web’s future focused on how the basic information structure and hyperlinking mechanism introduced by HTTP would be used by a variety of devices and platforms. As such, her use of the “2.0” designation refers to a next version of the Web that does not directly relate to the term’s current use.

The term Web 2.0 did not resurface until 2002. These authors focus on the concepts currently associated with the term where, as Scott Dietzen puts it, “the Web becomes a universal, standards-based integration platform”. John Robb wrote: “What is Web 2.0? It is a system that breaks with the old model of centralized Web sites and moves the power of the Web/Internet to the desktop.”

In 2004, the term began its rise in popularity when O’Reilly Media and MediaLive hosted the first Web 2.0 conference. In their opening remarks, John Battelle and Tim O’Reilly outlined their definition of the “Web as Platform”, where software applications are built upon the Web as opposed to upon the desktop. The unique aspect of this migration, they argued, is that “customers are building your business for you”. They argued that the activities of users generating content (in the form of ideas, text, videos, or pictures) could be “harnessed” to create value. O’Reilly and Battelle contrasted Web 2.0 with what they called “Web 1.0”. They associated Web 1.0 with the business models of Netscape and the Encyclopædia Britannica Online. For example,

Netscape framed “the web as platform” in terms of the old software paradigm: their flagship product was the web browser, a desktop application, and their strategy was to use their dominance in the browser market to establish a market for high-priced server products. Control over standards for displaying content and applications in the browser would, in theory, give Netscape the kind of market power enjoyed by Microsoft in the PC market. Much like the “horseless carriage” framed the automobile as an extension of the familiar, Netscape promoted a “webtop” to replace the desktop, and planned to populate that webtop with information updates and applets pushed to the webtop by information providers who would purchase Netscape servers.

In short, Netscape focused on creating software, updating it on occasion, and distributing it to the end users. O’Reilly contrasted this with Google, a company that did not at the time focus on producing software, such as a browser, but instead on providing a service based on data such as the links Web page authors make between sites. Google exploits this user-generated content to offer Web search based on reputation through its “PageRank” algorithm. Unlike software, which undergoes scheduled releases, such services are constantly updated, a process called “the perpetual beta”. A similar difference can be seen between the Encyclopædia Britannica Online and Wikipedia: while the Britannica relies upon experts to create articles and releases them periodically in publications, Wikipedia relies on trust in anonymous users to constantly and quickly build content. Wikipedia is not based on expertise but rather an adaptation of the open source software adage “given enough eyeballs, all bugs are shallow”, and it produces and updates articles constantly. O’Reilly’s Web 2.0 conferences have been held every year since 2004, attracting entrepreneurs, large companies, and technology reporters.

The term Web 2.0 was initially championed by bloggers and by technology journalists, culminating in the 2006 TIME magazine Person of The Year (You). That is, TIME selected the masses of users who were participating in content creation on social networks, blogs, wikis, and media sharing sites. In the cover story, Lev Grossman explains:

It’s a story about community and collaboration on a scale never seen before. It’s about the cosmic compendium of knowledge Wikipedia and the million-channel people’s network YouTube and the online metropolis MySpace. It’s about the many wresting power from the few and helping one another for nothing and how that will not only change the world but also change the way the world changes.


Web 2.0 sites allow users to do more than just retrieve information. Instead of merely ‘reading’, a user is invited to ‘write’ as well, or contribute to the content available to everyone in a user friendly way. By increasing what was already possible in “Web 1.0”, they provide the user with more user-interface, software and storage facilities, all through their browser. This has been called “network as platform” computing. Major features of Web 2.0 include social networking sites, user created Web sites, self-publishing platforms, tagging, and social bookmarking. Users can provide the data that is on a Web 2.0 site and exercise some control over that data. These sites may have an “architecture of participation” that encourages users to add value to the application as they use it. Some scholars have put forth cloud computing as an example of Web 2.0 because cloud computing is simply an implication of computing on the Internet.

The concept of Web-as-participation-platform captures many of these characteristics. Bart Decrem, a founder and former CEO of the purpose-built social networking oriented and now discontinued Flock Web browser project, calls Web 2.0 the “participatory Web” and regards the Web-as-information-source as Web 1.0.

Web 2.0 offers all users the same freedom to contribute. While this opens the possibility for serious debate and collaboration, it also increases the incidence of “spamming” and “trolling” by unscrupulous or misanthropic users. The impossibility of excluding group members who don’t contribute to the provision of goods from sharing profits gives rise to the possibility that serious members will prefer to withhold their contribution of effort and free ride on the contribution of others. This requires what is sometimes called radical trust by the management of the Web site. According to Best, the characteristics of Web 2.0 are: rich user experience, user participation, dynamic content, metadata, Web standards, and scalability. Further characteristics, such as openness, freedom and collective intelligence by way of user participation, can also be viewed as essential attributes of Web 2.0.

The key features of Web 2.0  include:

  1. Folksonomy- free classification of information; allows users to collectively classify and find information (e.g. Tagging)
  2. Rich User Experience- dynamic content; responsive to user input
  3. User as a Contributor- information flows two ways between site owner and site user by means of evaluation, review, and commenting
  4. Long tail- services offered on demand basis; profit is realized through monthly service subscriptions more than one-time purchases of goods over the network
  5. User Participation- site users add content for others to see (e.g. Crowdsourcing)
  6. Basic Trust- contributions are available for the world to use, reuse, or re-purpose
  7. Dispersion- content delivery uses multiple channels (e.g. file sharing, permalinks); digital resources and services are sought more than physical goods
  8. Mass Participation


The client-side (Web browser) technologies used in Web 2.0 development include Ajax and JavaScript frameworks such as YUI Library, Dojo Toolkit, MooTools, jQuery, Ext JS and Prototype JavaScript Framework. Ajax programming uses JavaScript to upload and download new data from the Web server without undergoing a full page reload.

To allow users to continue to interact with the page, communications such as data requests going to the server are separated from data coming back to the page (asynchronously). Otherwise, the user would have to routinely wait for the data to come back before they can do anything else on that page, just as a user has to wait for a page to complete the reload. This also increases overall performance of the site, as the sending of requests can complete quicker independent of blocking and queueing required to send data back to the client.

The data fetched by an Ajax request is typically formatted in XML or JSON (JavaScript Object Notation) format, two widely used structured data formats. Since both of these formats are natively understood by JavaScript, a programmer can easily use them to transmit structured data in their Web application. When this data is received via Ajax, the JavaScript program then uses the Document Object Model (DOM) to dynamically update the Web page based on the new data, allowing for a rapid and interactive user experience. In short, using these techniques, Web designers can make their pages function like desktop applications. For example, Google Docs uses this technique to create a Web based word processor.

Adobe Flex is another technology often used in Web 2.0 applications. Compared to JavaScript libraries like jQuery, Flex makes it easier for programmers to populate large data grids, charts, and other heavy user interactions. Applications programmed in Flex are compiled and displayed as Flash within the browser. As a widely available plugin independent of W3C standards (the World Wide Web Consortium is the governing body of Web standards and protocols), Flash is capable of doing many things that were not possible pre-HTML5. Of Flash’s many capabilities, the most commonly used in Web 2.0 is its ability to play audio and video files. This has allowed for the creation of Web 2.0 sites where video media is seamlessly integrated with standard HTML. With the introduction of HTML5 in 2010, the role of Flash is decreasing. HTML5 offers many new technologies that allow content to be delivered to users in a more streamlined and personalized manner. These include support for scalable vector graphics (SVG), and the ability to store Web session state data on a client-side and browser based database rather than cookies. Additionally, HTML5 video has been proven to decrease the amount of computer resources required, compared to Adobe’s Flash; Apple Inc. demonstrated that the use of Flash on mobile devices decreases battery lifespan significantly. In November 2011, Adobe announced that they will no longer publish future public versions of the mobile Flash plugin.

In addition to Flash and Ajax, JavaScript/Ajax frameworks have recently become a very popular means of creating Web 2.0 sites. At their core, these frameworks use the same technology as JavaScript, Ajax, and the DOM. However, frameworks smooth over inconsistencies between Web browsers and extend the functionality available to developers. Many of them also come with customizable, prefabricated ‘widgets’ that accomplish such common tasks as picking a date from a calendar, displaying a data chart, or making a tabbed panel.

On the server-side, Web 2.0 uses many of the same technologies as Web 1.0. Languages such as PHP, Ruby, Perl, Python, as well as Enterprise Java (J2EE) and Microsoft.NET Framework, are used by developers to output data dynamically using information from files and databases. What has begun to change in Web 2.0 is the way this data is formatted. In the early days of the Internet, there was little need for different Web sites to communicate with each other and share data. In the new “participatory Web”, however, sharing data between sites has become an essential capability. To share its data with other sites, a Web site must be able to generate output in machine-readable formats such as XML (Atom, RSS, etc.) and JSON. When a site’s data is available in one of these formats, another Web site can use it to integrate a portion of that site’s functionality into itself, linking the two together. When this design pattern is implemented, it ultimately leads to data that is both easier to find and more thoroughly categorized, a hallmark of the philosophy behind the Web 2.0 movement.


Web 2.0 can be described in three parts:

  • Rich Internet application (RIA) — defines the experience brought from desktop to browser whether it is from a graphical point of view or usability point of view. Some buzzwords related to RIA are Ajax and Flash.
  • Web-oriented architecture (WOA) — is a key piece in Web 2.0, which defines how Web 2.0 applications expose their functionality so that other applications can leverage and integrate the functionality providing a set of much richer applications. Examples are feeds, RSS, Web Services, mash-ups.
  • Social Web — defines how Web 2.0 tends to interact much more with the end user and make the end-user an integral part.

As such, Web 2.0 draws together the capabilities of client- and server-side software, content syndication and the use of network protocols. Standards-oriented Web browsers may use plug-ins and software extensions to handle the content and the user interactions. Web 2.0 sites provide users with information storage, creation, and dissemination capabilities that were not possible in the environment now known as “Web 1.0”.

Web 2.0 sites include the following features and techniques, referred to as the acronym SLATES by Andrew McAfee:

Finding information through keyword search.
Connects information together into a meaningful information ecosystem using the model of the Web, and provides low-barrier social tools.
The ability to create and update content leads to the collaborative work of many rather than just a few Web authors. In wikis, users may extend, undo and redo each other’s work. In blogs, posts and the comments of individuals build up over time.
Categorization of content by users adding “tags” — short, usually one-word descriptions — to facilitate searching, without dependence on pre-made categories. Collections of tags created by many users within a single system may be referred to as “folksonomies” (i.e., folk taxonomies).
Software that makes the Web an application platform as well as a document server. These include software like Adobe Reader, Adobe Flash, Microsoft Silverlight, ActiveX, Oracle Java, QuickTime, Windows Media, etc.
The use of syndication technology, such as RSS to notify users of content changes.

While SLATES forms the basic framework of Enterprise 2.0, it does not contradict all of the higher level Web 2.0 design patterns and business models. In this way, a new Web 2.0 report from O’Reilly is quite effective and diligent in interweaving the story of Web 2.0 with the specific aspects of Enterprise 2.0. It includes discussions of self-service IT, the long tail of enterprise IT demand, and many other consequences of the Web 2.0 era in the enterprise. The report also makes many sensible recommendations around starting small with pilot projects and measuring results, among a fairly long list.

Web 2.0 in education

Web 2.0 technologies can provide students with more engagement through greater customization and choice of topics, and less distraction from their peers.

Will Richardson stated in Blogs, Wikis, Podcasts and other Powerful Web tools for the Classrooms, 3rd Edition that, “The Web has the potential to radically change what we assume about teaching and learning, and it presents us with important questions to ponder: What needs to change about our curriculum when our students have the ability to reach audiences far beyond our classroom walls?” Web 2.0 tools are needed in the classroom to prepare both students and teachers for the shift in learning that Collins and Halverson describe. According to Collins and Halverson, the self-publishing aspects as well as the speed with which their work becomes available for consumption allows teachers to give students the control they need over their learning. This control is the preparation students will need to be successful as learning expands beyond the classroom.”

By allowing students to use the technology tools of Web 2.0, teachers are giving students the opportunity to share what they learn with peers. Some are concerned that these technologies could hinder the personal interaction of students: “Social networking sites have worried many educators (and parents) because they often bring with them outcomes that are not positive: narcissism, gossip, wasted time, ‘friending’, hurt feelings, ruined reputations, and sometimes unsavory, even dangerous activities”.

Web 2.0 calls for major shifts in the way education is provided for students. One of the biggest shifts that Will Richardson points out in his book Blogs, Wikis, Podcasts, and Other Powerful Web Tools for Classrooms[43] is the fact that education should be collaboratively constructed. This means that students, in a Web 2.0 classroom, are expected to collaborate with their peers. By making the shift to a Web 2.0 classroom, teachers are creating a more open atmosphere where students are expected to stay engaged and participate in class discussions. In fact, there are many ways for educators to use Web 2.0 technologies in their classrooms.

“Weblogs are not built on static chunks of content. Instead they are comprised of reflections and conversations that in many cases are updated every day […] They demand interaction.”[43] Will Richardson’s observation of the essence of Weblogs speaks directly to why blogs are so well suited to discussion based classrooms. As long as the students are invested in the project, Weblogs give students a public space to interact with one another and the content of the class.

For example, Laura Rochette implemented the use of blogs in her American History class and noted that in addition to an overall improvement in quality, the use of the blogs as an assignment demonstrated synthesis level activity from her students. In her experience, asking students to conduct their learning in the digital world meant asking students “to write, upload images, and articulate the relationship between these images and the broader concepts of the course, [in turn] demonstrating that they can be thoughtful about the world around them.”

Web 2.0 and philanthropy

The spread of participatory information-sharing over the world, combined with recent improvements in lower cost internet access in developing countries, has opened up new possibilities for peer-to-peer charities, which allow individuals to contribute small amounts to charitable projects for other individuals. Web sites such as Donors Choose and Global Giving now allow small-scale donors to direct funds to individual projects of their choice.

A popular twist on internet-based philanthropy is the use of peer-to-peer lending for charitable purposes. Kiva pioneered this concept in 2005, offering the first Web-based service to publish individual loan profiles for funding. Kiva raises funds for local intermediary microfinance organizations which post stories and updates on behalf of the borrowers. Lenders can contribute as little as $25 to loans of their choice, and receive their money back as borrowers repay. Kiva falls short of being a pure peer-to-peer charity, in that loans are disbursed before being funded by lenders and borrowers do not communicate with lenders themselves. However, the recent spread of cheap internet access in developing countries has made genuine peer-to-peer connections increasingly feasible. In 2009 the US-based nonprofit Zidisha tapped into this trend to offer the first peer-to-peer microlending platform to link lenders and borrowers across international borders without local intermediaries. Inspired by interactive Web sites, such as Facebook and eBay, Zidisha’s microlending platform facilitates direct dialogue between lenders and borrowers and a performance rating system for borrowers. Web users worldwide can fund loans for as little as a dollar.

Web 2.0 in social work

The social work profession is embracing Web 2.0 technologies. One of the first references to Social Work 2.0 was made in “The New Social Worker” magazine, which was started by Linda May Grobman, MSW, ACSW, LSW, in spring of 1994. This online publication continues to explore the application of Web 2.0 technology within the social work community. The first article of an ongoing SW 2.0 series was entitled “Caring Bridge: A Valuable Tool for Social Workers and Those With Critical Illness,” written by Karen Zgoda, MSW, LCSW. It was followed by a column entitled, “Social Work? There’s a Blog for That,” by Karen Zgoda.The article noted that blogging was quickly becoming a phenomenon within the social work community. Both students and professionals had begun chronicling their career development as well as sharing information from their respective practice areas. In 2007, Jonathan Singer, Ph.D. started The Social Work Podcast, which provides information about all things social work, followed by a more formalized outline of the meaning of Social Work 2.0 in 2009.

In 2010, Social Work Today Magazine analyzed the disconnect between the social work community and the under utilization of advanced technologies in social work organizations. Meanwhile, mobile technology was changing the way society accessed the World Wide Web and communicated with each other. With the expansion of mobile technology, the National Association of Social Workers (NASW) published a 2010 study investigating child welfare workers’ attitudes towards mobile technology tools. Social workers realize the potential that technology presents in expanding their ability to connect with each other and service users as reported by The Guardian in an April 7, 2011 article. As time and technology evolve, the social work profession is expanding with it.

Web-based applications and desktops

Ajax has prompted the development of Web sites that mimic desktop applications, such as word processing, the spreadsheet, and slide-show presentation. In 2006 Google, Inc. acquired one of the best-known sites of this broad class, Writely. WYSIWYG wiki and blogging sites replicate many features of PC authoring applications.

Several browser-based services have emerged, including EyeOS and YouOS.(No longer active.) Although named operating systems, many of these services are application platforms. They mimic the user experience of desktop operating-systems, offering features and applications similar to a PC environment, and are able to run within any modern browser. However, these so-called “operating systems” do not directly control the hardware on the client’s computer.

Numerous web-based application services appeared during the dot-com bubble of 1997–2001 and then vanished, having failed to gain a critical mass of customers. In 2005, WebEx acquired one of the better-known of these, Intranets.com, for $45 million.

Web 3.0

Definitions of Web 3.0 vary greatly. Some believe its most important features are the Semantic Web and personalization. Focusing on the computer elements, Conrad Wolfram has argued that Web 3.0 is where “the computer is generating new information”, rather than humans.

Andrew Keen, author of The Cult of the Amateur, considers the Semantic Web an “unrealisable abstraction” and sees Web 3.0 as the return of experts and authorities to the Web. For example, he points to Bertelsmann’s deal with the German Wikipedia to produce an edited print version of that encyclopedia. CNN Money’s Jessi Hempel expects Web 3.0 to emerge from new and innovative Web 2.0 services with a profitable business model.

Futurist John Smart, lead author of the Metaverse Roadmap, defines Web 3.0 as the first-generation Metaverse (convergence of the virtual and physical world), a Web development layer that includes TV-quality open video, 3D simulations, augmented reality, human-constructed semantic standards, and pervasive broadband, wireless, and sensors. Web 3.0’s early geosocial (Foursquare, etc.) and augmented reality (Layar, etc.) Webs are an extension of Web 2.0’s participatory technologies and social networks (Facebook, etc.) into 3D space. Of all its metaverse-like developments, Smart suggests Web 3.0’s most defining characteristic will be the mass diffusion of NTSC-or-better quality video to TVs, laptops, tablets, and mobile devices, a time when “the internet swallows the television.” Smart considers Web 3.0 to be the Semantic Web and in particular, the rise of statistical, machine-constructed semantic tags and algorithms, driven by broad collective use of conversational interfaces, perhaps circa 2020. David Siegel’s perspective in Pull: The Power of the Semantic Web, 2009, is consonant with this, proposing that the growth of human-constructed semantic standards and data will be a slow, industry-specific incremental process for years to come, perhaps unlikely to tip into broad social utility until after 2020.

According to some Internet experts, Web 3.0 will enable the use of autonomous agents to perform some tasks for the user. Rather than having search engines gear towards your keywords, the search engines will gear towards the user.

The current Research & Development Focus of the United States – Department of Defense’s Advanced Distributed Learning (ADL) Initiative describes these autonomous agents as the personal assistants to the Next Generation Learner in the Next Generation Learner Environment. The Personal Assistant for Learning (PAL) is a long-term focus of ADL’s R&D endeavors over the next 10–15 years. The goal of this research is to create a capability that anticipates learner needs, seamlessly integrates yet-to-be available information, and provides ubiquitous access to effective, personalized learning content and/or job performance aids that can be accessed from multiple non-invasive devices and platforms.