Web 2.0

The term Web 2.0 refers to a second generation of services available on the World Wide Web that lets people collaborate and share information online. In contrast to the first generation, Web 2.0 gives users an experience closer to desktop applications than the traditional static Web pages. Web 2.0 applications often use a combination of techniques devised in the late 1990s, including public web service APIs (dating from 1998), Ajax (1998), and web syndication (1997). They often allow for mass participation (web-based social software). The concept may include blogs and wikis.

O'Reilly Media and MediaLive International popularized the term as the name for a series of web development conferences that started in October 2004. CMP Media, which purchased MediaLive, claims the term as a service mark for live events, reserving exclusive use of the term for its own conferences.

Some members of the development community see Web 2.0 as an overly vague buzzword, incorporating whatever is newly popular on the Web (such as tags and podcasts), without having any fixed meaning.

Introduction
With its allusion to the version numbers that commonly designate software upgrades, the phrase Web 2.0 trendily hints at an improved form of the World Wide Web, and the term has been in occasional use for several years. The more explicit synonym "Participatory Web", emphasizing tools and platforms that enable the user to tag, blog, comment, modify, augment, select from, rank, and generally talk back to the contributions of other users and the general world community has increasingly seen use as an alternative phrase. Some commentators regard reputation-based public wikis, like Wikipedia, as pioneering examples of Web 2.0/Participatory Web technology. O'Reilly Media and MediaLive International popularized the term Web 2.0 for a conference they hosted after Dale Dougherty mentioned it during a brainstorming session. Dougherty suggested that the Web was in a renaissance, with changing rules and evolving business models. The participants assembled examples &mdash; "DoubleClick was Web 1.0; Google AdSense is Web 2.0. Ofoto is Web 1.0; Flickr is Web 2.0" &mdash; rather than definitions. Dougherty recruited John Battelle for a business perspective, and it became the first Web 2.0 Conference in October 2004. A second annual conference was held in October 2005.

In their first conference opening talk, O'Reilly and Battelle summarized key principles they believe characterize Web 2.0 applications: the Web as platform; data as the driving force; network effects created by an architecture of participation; innovation in assembly of systems and sites composed by pulling together features from distributed, independent developers (a kind of "open source" development); lightweight business models enabled by content and service syndication; the end of the software adoption cycle ("the perpetual beta"); software above the level of a single device, leveraging the power of The Long Tail.

Earlier users of the phrase Web 2.0 employed it as as a synonym for semantic web, and indeed, the two concepts complement each other. The combination of social networking systems such as FOAF and XFN with the development of tag-based folksonomies and delivered through blogs and wikis creates a natural basis for a semantic environment. Although the technologies and services that comprise Web 2.0 are less powerful than an internet in which the machines can understand and extract meaning, as proponents of the Semantic Web envision, Web 2.0 represents a step in its direction.

As used by its proponents, the phrase refers to one or more of the following:


 * The transition of websites from isolated information silos to sources of content and functionality, thus becoming computing platforms serving web applications to end users
 * A social phenomenon referring to an approach to creating and distributing Web content itself, characterized by open communication, decentralization of authority, freedom to share and re-use, and "the market as a conversation"
 * A more organized and categorized content, with a far more developed deeplinking web architecture
 * A shift in economic value of the web, possibly surpassing that of the dot com boom of the late 1990s
 * A marketing term to differentiate new web businesses from those of the dot com boom, which due to the bust now seem discredited
 * The resurgence of excitement around the possibilities of innovative web applications and services that gained a lot of momentum around mid 2005

Many find it easiest to define Web 2.0 by associating it with companies or products that embody its principles. Some of the more well known Web 2.0 entities are Google Maps, Flickr, del.icio.us, digg, last.fm, and Technorati.

Many recently-developed concepts and technologies are seen as contributing to Web 2.0, including weblogs, linklogs, wikis, podcasts, RSS feeds and other forms of many to many publishing; social software, web APIs, web standards, online web services, and others.

Proponents of the Web 2.0 concept say that it differs from early web development (retrospectively labeled Web 1.0) in that it moves away from static websites, the use of search engines, and surfing from one website to the next, towards a more dynamic and interactive World Wide Web. Others argue that the original and fundamental concepts of the WWW are not actually being superseded. Skeptics argue that the term is little more than a buzzword, or that it means whatever its proponents want it to mean in order to convince their customers, investors and the media that they are creating something fundamentally new, rather than continuing to develop and use well-established technologies.



The retrospectively-labelled "Web 1.0" often consisted of static HTML pages that were updated rarely, if at all. They depended solely on HTML, which a new Internet user could learn fairly easily. The success of the dot-com era depended on a more dynamic Web (sometimes labeled Web 1.5) where content management systems served dynamic HTML web pages created on the fly from a content database that could more easily be changed. In both senses, so-called eyeballing was considered intrinsic to the Web experience, thus making page hits and visual aesthetics important factors.

Proponents of the Web 2.0 approach believe that Web usage has started increasingly moving towards interaction and towards rudimentary social networks, which can serve content that exploits network effects with or without creating a visual, interactive web page. In one view, Web 2.0 sites act more as points of presence, or user-dependent web portals, than as traditional websites. They have become so advanced new internet users cannot create these websites, they are only users of web services, done by specialist professional experts.

Access to consumer-generated content facilitated by Web 2.0 brings the web closer to Tim Berners-Lee's original concept of the web as a democratic, personal, and DIY medium of communication.

Market drivers of Web 2.0
While the term might have appeared out of nowhere, the underlying fundamentals of this evolutionary shift stay the same:


 * Broadband has become mainstream and ubiquitous, resulting in an increased usage of the Internet for even small tasks on different devices
 * More people go online for a variety of tasks and shopping-related activities
 * The founders and executive management of the first batch of companies have moved on - either joined one of the big players, left to join Venture Capital companies, or started or joined a completely new thing. This means a lot of experience of what did and didn't work is in the mix
 * New ventures can grow more slowly — barriers to entry are lower, there's less pressure to gain venture capital, less hype to cater to
 * New browsers becoming mainstream are capable of supporting advanced AJAX and other technologies

New web-based communities
Some websites that potentially sit under the Web 2.0 umbrella have created new online social networks amongst the general public. Some of the websites run social software where people work together. Other websites reproduce several individuals' RSS feeds on one page. Other ones provide deeplinking between individual websites.

The syndication and messaging capabilities of Web 2.0 have fostered, to a greater or lesser degree, a tightly-woven social fabric among individuals. Arguably, the nature of web-based communities has changed in recent months and years. The meaning of these changes, however, has pundits divided. Basically, ideological lines run thusly: Web 2.0 either empowers the individual and provides an outlet for the 'voice of the voiceless'; or it elevates the amateur to the detriment of professionalism, expertise and clarity.

New web-based applications and desktops
The richer user-experience afforded by Ajax has prompted the development of web sites that mimic personal computer applications, such as word processing, the spreadsheet, and slide-show presentation. Wysiwyg wiki sites replicate many features of PC authoring applications. Still other sites perform collaboration and project management functions. Java enables sites that provide computation-intensive video capability. One of the best known sites of this broad class, Writely, was acquired by Google in early 2006.

Several browser-based "operating systems" or "online desktops" have also appeared. They are essentially application platforms, not operating systems per se. These services mimic the user experience of desktop operating systems, offering features and applications similar to a PC environment. The primary difference is that they can be used from any modern browser.

Numerous web-based application services appeared during the Dot-com bubble and then vanished, having failed to gain a critical mass of customers. The best known of these, Intranets.com was acquired in 2005 by WebEx for slightly more than the total it had raised in venture capital, after six years in business.

General characteristics
While the definition of a Web 2.0 application is still hotly debated, it is generally accepted that a Web 2.0 website would exhibit some basic characteristics. These include:


 * The site should not act as a walled garden - it should be easy to get data in and out of the system.
 * Users usually own their data on the site and can modify it at their convenience.
 * Mainly web-based - most successful Web 2.0 applications can be used almost entirely through a web browser: this is commonly referred to by the phrase "network as platform".
 * Data returns should be dynamic, not static, changing depending on variables associated with the user's query (e.g. keywords, location).
 * An architecture of participation that allows users to add value to the application as they use it.
 * Some social networking aspects.

Visual Elements
Many Web 2.0 websites assert priority to their visual design and aesthetics, with the intention of providing a clear, well-organized and visually appealing site. Common design techniques include:


 * Gradient backgrounds
 * Large colorful icons, often with reflections and drop shadows
 * Large text (especially in comparison with the emphasis on very small text in earlier designs)
 * Diagonal hatch backgrounds
 * Glossy three-dimensional elements
 * Apparently random highlights and call-outs in text

Technology overview
The complex and evolving technology infrastructure of Web 2.0 includes server software, content syndication, messaging protocols, standards-based browsers with plugins and extensions, and various client applications. These differing but complementary approaches provide Web 2.0 with information storage, creation, and dissemination capabilities that go beyond what was formerly expected of websites.

A Web 2.0 website typically features a number of the following techniques:


 * Unobtrusive rich Internet application techniques (such as Ajax)
 * CSS
 * Semantically valid XHTML markup and/or the use of Microformats
 * Syndication and aggregation of data in RSS/Atom
 * Clean and meaningful URLs
 * Weblog publishing
 * Mashups
 * REST or XML Webservice APIs

Rich Internet applications
Recently, rich Internet application techniques such as Ajax have evolved that can improve the user-experience in browser-based web applications. Ajax involves a web page requesting an update for some part of its content, and altering that part in the browser, without refreshing the whole page at the same time. There are proprietary implementations (as in Google Maps) and open forms that can utilise web service APIs, syndication feeds, or even screen scraping.

Server-side software
The functionality of Web 2.0 rich Internet applications builds on the existing web server architecture, but puts much greater emphasis on back-end software. Syndication differs only nominally from dynamic content management publishing methods, but web services typically require much more robust database and workflow support, and become very similar to the traditional intranet functionality of an application server. Vendor approaches to date fall under either a universal server approach, which bundles most of the necessary functionality in a single server platform, or a web-server plugin approach, which uses standard publishing tools enhanced with API interfaces and other tools. Advocates of the evolutionary path toward Web 2.0 do not expect significant alteration in development to result from the different approaches selected.

Client-side software
The extra functionality provided by Web 2.0 depends on users being able to work with the data stored on servers. This can be through forms in an HTML page, a scripting language such as Javascript, or through Flash or Java. These methods all make use of the client computer to reduce the server workload.

RSS
The first and the most important evolution towards Web 2.0 involves the syndication of website content, using standardized protocols which permit end-users to make use of a site's data in another context, ranging from another website, to a browser plugin, or to a separate desktop application. Protocols which permit syndication include RSS (Really Simple Syndication), RDF (as in RSS 1.1), and Atom, all of them flavors of XML. Specialized protocols such as FOAF and XFN (both for social networking) extend functionality of sites or permit end-users to interact without centralized websites. See microformats for more specialized data formats.

Due to the recent development of these trends, many of these protocols remain de facto (rather than formal) standards.

RSS is also known as web syndication.

Web protocols
Web communication protocols provide a key element of the Web 2.0 infrastructure. Major protocols include REST and SOAP.


 * REST (Representational State Transfer) indicates a way to access and manipulate data on a server using the HTTP verbs GET, POST, PUT, and DELETE
 * SOAP involves POSTing XML messages and requests to a server that may contain quite complex, but pre-defined, instructions for it to follow

In both cases, access to the service is defined by an API. Often this API is specific to the server, but standard web service APIs (for example, for posting to a blog) are also widely used. Most, but not all, communications with web services involve some form of XML (eXtensible Markup Language).

See also WSDL (Web Services Description Language), which is the standard way of publishing a SOAP API, and the list of Web service specifications for links to many other web service standards, including those many whose names begin 'WS-'.

Criticism
Given the lack of set standards as to what "Web 2.0" actually means, implies, or requires, the term can mean radically different things to different people. For instance, many people pushing Web 2.0 talk about well-formed, validated HTML; however, not many production sites actually adhere to this standard. Many people will also talk about web sites "degrading gracefully" (designing a website so that its fundamental features remain useable by people who access it with software that does not support every technology employed by the site); however, the addition of Ajax scripting to websites can render the website completely unusable to anyone browsing with JavaScript turned off, or using a slightly older browser. Many have complained that the proliferation of Ajax scripts, along with unknowledgeable webmasters, has increased the instances of "tag soup": websites where  tags, and other semantically useless tags, are thrown about the HTML file with little organization in mind, in a way that was more commonly done during the dot-com boom, and is something many standards proponents have been trying to move away from.

Many of the ideas of Web 2.0 have been employed on networked systems that were around well before the term was developed; Amazon.com, for instance, has allowed users to write reviews and consumer guides since its inception, in a form of self-publishing, and opened up its API to outside developers in 2002. Prior art also comes from research in Computer Supported Collaborative Learning and Computer Supported Cooperative Work.

Conversely, when a website proclaims itself "Web 2.0" for the use of some trivial feature such as blogs or gradient boxes, it is generally considered to be more of an attempt at self-promotion than an actual endorsement of the ideas behind Web 2.0. It has sometimes been reduced to simply a marketing buzzword, like 'synergy', that can mean whatever a salesperson wants it to do, with little connection to most of the good, but unrelated ideas that it is based on. The argument also exists that "Web 2.0" does not represent a new version of World Wide Web at all, but merely continues to use "Web 1.0" technologies and concepts.

Other criticism has included the term "a second bubble" stating that there are too many Web 2.0 companies attempting to create the same product with a lack of business models.

Some venture capitalists have noted that there are too few users of the second generation of web applications to make them an economically-viable target for consumer applications. Josh Kopelman famously noted that Web 2.0 only is exciting for 53,651 people, the number of subscribers to TechCrunch, a popular weblog that covers the internet industry.

Trademark controversy
In November 2003, CMP Media applied to the USPTO for a service mark on the use of the term "WEB 2.0" for live events. On the basis of this application, CMP Media sent a cease and desist demand to the Irish non-profit organization IT@Cork on May 24, 2006, but retracted two days later. The "WEB 2.0" service mark registration passed final PTO Examining Attorney review on May 10, 2006, but as of June 12, 2006 the PTO has not published the mark for opposition. The European Union application (which would confer unambigious status in Ireland) is pending (app no 004972212); it was filed on March 23, 2006.

Web 2.0 service providers

 * An image of many web2.0 company logos
 * Flickr - Image sharing
 * Flagr - Location bookmarking
 * Technorati - Blog search
 * last.fm - Music portal
 * Pandora - Intelligent music player
 * Wordpress - Weblog service

Web 2.0 blogs

 * eHub
 * Mashable
 * O'Reilly Radar
 * Postbubble
 * Read/WriteWeb
 * Solution Watch
 * TechCrunch

Supportive

 * The State of Web 2.0 by Dion Hinchcliffe, April 2006
 * Google deal highlights Web 2.0 boom, Martin LaMonica CNET News.com, March 14, 2006
 * What is Web 2.0?, by Tim O'Reilly, September 30, 2005
 * We Are the Web, by Kevin Kelly, August 2005
 * Web 2.0 for Designers, by Richard MacManus & Joshua Porter, May 4, 2005
 * Web 2.0 articles and help for beginners, by Victor Rottenstein, Jul 26, 2006

Critical

 * The Enzyme that Won from The Economist, May 2006
 * The new Internet "boom" doesn't live up to its name. Slate.com, March 29, 2006
 * Web 2.0 Baloney, by John C. Dvorak, March 1, 2006
 * Web 3.0, by Jeffrey Zeldman, January 16, 2006
 * Web 2.0? It doesn't exist, by Russell Shaw, December 17, 2005
 * Web 2.0, by Paul Graham, November 2005
 * Web 2.0: It's ... like your brain on LSD!, by Andrew Orlowski, October 21, 2005
 * The amorality of Web 2.0, by Nicholas G. Carr, March 10, 2005

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