View source for Web 2.0

{{short description|Websites that use technology beyond the static pages of the early Internet}}
{{pp-move}}
[[File:Web 2.0 Map.svg|thumb|300px|A [[tag cloud]] (a typical Web 2.0 phenomenon in itself) presenting Web 2.0 themes]]

'''Web 2.0''' (also known as '''participative''' (or '''participatory''')<ref>{{Cite journal|last1=Blank|first1=Grant|last2=Reisdorf|first2=Bianca|date=2012-05-01|title=The Participatory Web|url=https://www.researchgate.net/publication/263266131|journal=Information|volume=15|issue=4|pages=537–554|doi=10.1080/1369118X.2012.665935|s2cid=143357345|issn = 1369-118X}}</ref> '''web''' and '''social web''')<ref name=":42">{{Cite news|title=What is Web 1.0? - Definition from Techopedia|language=en|work=Techopedia.com|url=https://www.techopedia.com/definition/27960/web-10|url-status=live|access-date=2018-07-13|archive-url=https://web.archive.org/web/20180713204908/https://www.techopedia.com/definition/27960/web-10|archive-date=2018-07-13}}</ref> refers to [[website]]s that emphasize [[user-generated content]], [[usability|ease of use]], [[participatory culture]], and [[interoperability]] (i.e., compatibility with other products, systems, and devices) for [[end user]]s.

The term was coined by [[Darcy DiNucci]] in 1999<ref name="DiNucci">
{{cite journal|last=DiNucci|first=Darcy|year=1999|title=Fragmented Future|url=http://darcyd.com/fragmented_future.pdf|url-status=live|journal=Print|volume=53|issue=4|page=32|archive-url=https://web.archive.org/web/20111110143942/http://darcyd.com/fragmented_future.pdf|archive-date=2011-11-10|access-date=2011-11-04}}
</ref> and later popularized by [[Tim O'Reilly]] and [[Dale Dougherty]] at the first [[Web 2.0 Summit|Web 2.0 Conference]] in 2004.<ref name="graham">{{cite web |url=http://www.paulgraham.com/web20.html |title=Web 2.0 |first=Paul |last=Graham |author-link=Paul Graham (computer programmer) |date=November 2005 |access-date=2006-08-02 |quote=I first heard the phrase 'Web 2.0' in the name of the Web 2.0 conference in 2004. |archive-url=https://web.archive.org/web/20121010024704/http://www.paulgraham.com/web20.html |archive-date=2012-10-10 |url-status=live }}</ref><ref name="oreilly">{{cite web |url=http://www.oreillynet.com/pub/a/oreilly/tim/news/2005/09/30/what-is-web-20.html |title=What Is Web 2.0 |publisher=O'Reilly Network |first=Tim |last=O'Reilly |author-link=Tim O'Reilly |date=2005-09-30 |access-date=2006-08-06 |archive-url=https://web.archive.org/web/20130424204457/http://oreilly.com/web2/archive/what-is-web-20.html |archive-date=2013-04-24 |url-status=live }}</ref><ref>{{cite web |last=Strickland |first=Jonathan |url=http://computer.howstuffworks.com/web-20.htm |title=How Web 2.0 Works |website=computer.howstuffworks.com |date=2007-12-28 |access-date=2015-02-28 |archive-url=https://web.archive.org/web/20150217030750/http://computer.howstuffworks.com/web-20.htm |archive-date=2015-02-17 |url-status=live }}</ref> Although the term mimics the numbering of [[software versions]], it does not denote a formal change in the nature of the [[World Wide Web]],<ref>{{Cite journal |last=Sykora |first=M. |date=2017 |title=Web 1.0 to Web 2.0: an observational study and empirical evidence for the historical r(evolution) of the social web |journal=  International Journal of Web Engineering and Technology|volume=12 |page=70 |doi=10.1504/IJWET.2017.084024 |s2cid=207429020 |url=https://figshare.com/articles/journal_contribution/9504914 }}</ref> but merely describes a general change that occurred during this period as interactive websites proliferated and came to overshadow the older, more static websites of the original Web.<ref name=":42"/>

A Web 2.0 website allows users to interact and collaborate through [[social media]] dialogue as creators of [[user-generated content]] in a [[virtual community]]. This contrasts the first generation of [[#Web 1.0|Web 1.0]]-era websites where people were limited to passively viewing content. Examples of Web 2.0 features include [[social networking site]]s or [[social media]] sites (e.g., [[Facebook]]), [[blog]]s, [[wiki]]s, [[Folksonomy|folksonomies]] ("tagging" keywords on websites and links), [[video sharing]] sites (e.g., [[YouTube]]), [[image sharing]] sites (e.g., [[Flickr]]), [[Web service|hosted services]], [[Web application]]s ("apps"), [[collaborative consumption]] platforms, and [[Mashup (web application hybrid)|mashup applications]].

Whether Web 2.0 is substantially different from prior Web technologies has been challenged by World Wide Web inventor [[Tim Berners-Lee]], who describes the term as [[jargon]].<ref name="developerWorks Interviews: Tim Berners-Lee"/> His original vision of the Web was "a collaborative medium, a place where we [could] all meet and read and write".<ref>{{cite news |url=http://news.bbc.co.uk/2/hi/technology/4132752.stm |title=Berners-Lee on the read/write web |work=BBC News |date=2005-08-09 |access-date=2012-08-05 |archive-url=https://web.archive.org/web/20120901190414/http://news.bbc.co.uk/2/hi/technology/4132752.stm |archive-date=2012-09-01 |url-status=live }}</ref><ref>{{cite book|last=Richardson|first=Will|title=Blogs, Wikis, Podcasts, and Other Powerful Web Tools for Classrooms|year=2009|publisher=Corwin Press|location=California|isbn=978-1-4129-5972-8|url=https://archive.org/details/isbn_9781412959728|url-access=registration|edition=2nd|page=[https://archive.org/details/isbn_9781412959728/page/1 1]}}</ref> On the other hand, the term [[Semantic Web]] (sometimes referred to as Web 3.0)<ref>{{cite web|url=http://www.webopedia.com/TERM/W/Web_3_point_0.html|title=What is Web 3.0? Webopedia Definition|website=www.webopedia.com|date=September 1996 |language=en|access-date=2017-02-15|archive-url=https://web.archive.org/web/20170215200738/http://www.webopedia.com/TERM/W/Web_3_point_0.html|archive-date=2017-02-15|url-status=live}}</ref> was coined by Berners-Lee to refer to a web of content where the meaning can be processed by machines.<ref name="Berners-Lee">{{cite journal |last=Berners-Lee |first=Tim |author2=James Hendler |author3=Ora Lassila |title=The Semantic Web |journal=Scientific American |volume=410 |issue=6832 |pages=1023–4 |date=May 17, 2001 |url=https://kask.eti.pg.gda.pl/redmine/projects/sova/repository/revisions/master/entry/doc/Master%20Thesis%20(In%20Polish)/materials/10.1.1.115.9584.pdf |access-date=October 1, 2018 |archive-url=https://web.archive.org/web/20181001220459/https://kask.eti.pg.gda.pl/redmine/projects/sova/repository/revisions/master/entry/doc/Master%20Thesis%20(In%20Polish)/materials/10.1.1.115.9584.pdf |archive-date=October 1, 2018 |url-status=live |df=mdy-all |doi=10.1038/scientificamerican0501-34 |pmid=11323639 |bibcode=2001SciAm.284e..34B }}</ref>

==History==
{{Main|History of the World Wide Web}}

===Web 1.0===
Web 1.0 is a [[retronym]] referring to the first stage of the [[World Wide Web]]'s [[History of the World Wide Web|evolution]], from roughly 1989 to 2004. According to Graham Cormode and Balachander Krishnamurthy, "content creators were few in Web 1.0 with the vast majority of users simply acting as consumers of content".<ref>{{Cite journal|first=Graham Cormode|last=Balachander Krishnamurthy|title=Key differences between Web 1.0 and Web 2.0|journal=First Monday|volume=13|issue=6|date=2 June 2008|url=http://firstmonday.org/htbin/cgiwrap/bin/ojs/index.php/fm/article/view/2125/1972|access-date=23 September 2014|archive-url=https://web.archive.org/web/20121025113431/http://firstmonday.org/htbin/cgiwrap/bin/ojs/index.php/fm/article/view/2125/1972|archive-date=25 October 2012|url-status=live|df=dmy-all}}</ref> [[Personal web page]]s were common, consisting mainly of static pages hosted on [[Internet Service Provider|ISP]]-run [[web server]]s, or on [[free web hosting service]]s such as [[Tripod (web hosting)|Tripod]] and the now-defunct [[GeoCities]].<ref>{{cite web|url=http://cultureandcommunication.org/deadmedia/index.php/Geocities|title=Geocities – Dead Media Archive|website=cultureandcommunication.org|access-date=2014-09-23|archive-url=https://web.archive.org/web/20140524003656/http://cultureandcommunication.org/deadmedia/index.php/Geocities|archive-date=2014-05-24|url-status=live}}</ref><ref>{{cite web|url=http://www.pcworld.com/article/163765/So_Long_GeoCities_We_Forgot_You_Still_Existed.html|title=So Long, GeoCities: We Forgot You Still Existed|date=2009-04-23|access-date=2014-09-23|archive-url=https://web.archive.org/web/20141017090359/http://www.pcworld.com/article/163765/So_Long_GeoCities_We_Forgot_You_Still_Existed.html|archive-date=2014-10-17|url-status=live}}</ref> With Web 2.0, it became common for average web users to have social-networking profiles (on sites such as [[Myspace]] and [[Facebook]]) and personal blogs (sites like [[Blogger (service)|Blogger]], [[Tumblr]] and [[LiveJournal]]) through either a low-cost [[web hosting services|web hosting service]] or through a dedicated host. In general, content was generated dynamically, allowing readers to comment directly on pages in a way that was not common previously.{{Citation needed|date=September 2010}}

Some Web 2.0 capabilities were present in the days of Web 1.0, but were implemented differently. For example, a Web 1.0 site may have had a [[guestbook]] page for visitor comments, instead of a [[comment section]] at the end of each page (typical of Web 2.0). During Web 1.0, server performance and bandwidth had to be considered—lengthy comment threads on multiple pages could potentially slow down an entire site. [[Terry Flew]], in his third edition of ''New Media,'' described the differences between Web 1.0 and Web 2.0 as a

{{Blockquote|text="move from personal websites to blogs and blog site aggregation, from publishing to participation, from web content as the outcome of large up-front investment to an ongoing and interactive process, and from content management systems to links based on "tagging" website content using [[Keyword (Internet search)|keyword]]s ([[folksonomy]])."|sign=|source=}}

Flew believed these factors formed the trends that resulted in the onset of the Web 2.0 "craze".<ref>{{Cite book
  |title=New Media: An Introduction
  |last=Flew  |first=Terry
  |year=2008
  |edition=3rd
  |publisher=Oxford University Press  |location=Melbourne
  |page=19
}}</ref>

====Characteristics====
Some common design elements of a Web 1.0 site include:<ref>{{cite journal|last1=Viswanathan|first1=Ganesh|last2=Dutt Mathur|first2=Punit|last3=Yammiyavar|first3=Pradeep|title=From Web 1.0 to Web 2.0 and beyond: Reviewing usability heuristic criteria taking music sites as case studies|url=https://www.academia.edu/8381037|date=March 2010|place=Mumbai|access-date=20 February 2015|series=IndiaHCI Conference|archive-date=21 March 2022|archive-url=https://web.archive.org/web/20220321085849/https://www.academia.edu/8381037|url-status=live}}</ref>
* Static pages rather than [[dynamic HTML]].<ref>{{cite web|url=https://computer.howstuffworks.com/web-10.htm|title=Is there a Web 1.0?|date=January 28, 2008|website=HowStuffWorks|access-date=February 15, 2019|archive-url=https://web.archive.org/web/20190222191357/https://computer.howstuffworks.com/web-10.htm|archive-date=February 22, 2019|url-status=live|df=mdy-all}}</ref>
* Content provided from the server's [[File system|filesystem]] rather than a relational database management system ([[RDBMS]]).
* Pages built using [[Server Side Includes]] or [[Common Gateway Interface]] (CGI) instead of a [[web application]] written in a [[dynamic programming language]] such as [[Perl]], [[PHP]], [[Python (programming language)|Python]] or [[Ruby (programming language)|Ruby]].{{clarify|date=April 2021}}
* The use of [[HTML 3.2]]-era elements such as [[Framing (World Wide Web)|frames]] and tables to position and align elements on a page. These were often used in combination with [[spacer GIF]]s.{{Citation needed|date=September 2010}}
* Proprietary [[HTML]] extensions, such as the [[blink element|&lt;blink&gt;]] and [[marquee tag|&lt;marquee&gt;]] tags, introduced during the [[First Browser War|first browser war]].
* Online [[guestbook]]s.
* [[GIF]] buttons, graphics (typically 88×31 [[pixel]]s in size) promoting [[web browser]]s, [[operating system]]s, [[text editor]]s and various other products.
* HTML forms sent via [[email]]. Support for [[server side scripting]] was rare on [[shared server]]s during this period. To provide a feedback mechanism for web site visitors, [[mailto]] forms were used. A user would fill in a form, and upon clicking the form's submit button, their [[email client]] would launch and attempt to send an email containing the form's details. The popularity and complications of the mailto protocol led browser developers to incorporate [[email client]]s into their browsers.<ref>{{cite web|url=http://www.catb.org/esr/writings/taoup/html/ch13s04.html|title=The Right Size of Software|website=www.catb.org|access-date=2015-02-20|archive-url=https://web.archive.org/web/20150617002902/http://www.catb.org/esr/writings/taoup/html/ch13s04.html|archive-date=2015-06-17|url-status=live}}</ref>

===Web 2.0===
The term "Web 2.0" was coined by [[Darcy DiNucci]], an [[information architecture]] consultant, in her January 1999 article "Fragmented Future":<ref name="DiNucci"/><ref>Aced, Cristina. (2013). [https://www.researchgate.net/publication/266672416_Web_20_the_origin_of_the_word_that_has_changed_the_way_we_understand_public_relations Web 2.0: the origin of the word that has changed the way we understand public relations.] {{Webarchive|url=https://web.archive.org/web/20220416181119/https://www.researchgate.net/publication/266672416_Web_20_the_origin_of_the_word_that_has_changed_the_way_we_understand_public_relations |date=2022-04-16 }}</ref>

{{blockquote|text="The Web we know now, which loads into a [[Web browser|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.]] introduced its first web-capable [[personal digital assistant]] (supporting Web access with [[Wireless Application Protocol|WAP]]), DiNucci saw the Web "fragmenting" into a future that extended beyond the browser/PC combination it was identified with. She focused on how the basic information structure and hyper-linking mechanism introduced by [[HTTP]] would be used by a variety of devices and platforms. As such, her "2.0" designation refers to the 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.<ref>Idehen, Kingsley. 2003. RSS: INJAN (It's not just about news). Blog. Blog Data Space. August 21 [https://web.archive.org/web/20091128090508/http://www.openlinksw.com/dataspace/kidehen@openlinksw.com/weblog/kidehen@openlinksw.com's%20BLOG%20&#91;127&#93;/241 OpenLinkSW.com]</ref><ref>Idehen, Kingsley. 2003. Jeff Bezos Comments about Web Services. Blog. Blog Data Space. September 25. [http://www.openlinksw.com/blog/~kidehen/index.vspx?id=373 OpenLinkSW.com] {{Webarchive|url=https://web.archive.org/web/20100212074724/http://www.openlinksw.com/blog/~kidehen/index.vspx?id=373 |date=2010-02-12 }}</ref><ref name="Knorr, Eric 2003">Knorr, Eric. 2003. The year of Web services. CIO, December 15.</ref> Companies such as [[Amazon (company)|Amazon]], Facebook, [[Twitter]], and [[Google]], made it easy to connect and engage in online transactions. Web 2.0 introduced new features, such as [[multimedia]] content and interactive web applications, which mainly consisted of two-dimensional screens.<ref>{{Cite journal |last=Kshetri |first=Nir |date=2022-03-01 |title=Web 3.0 and the Metaverse Shaping Organizations' Brand and Product Strategies |url=https://ieeexplore.ieee.org/document/9770453 |journal=IT Professional |volume=24 |issue=2 |pages=11–15 |doi=10.1109/MITP.2022.3157206 |s2cid=248546789 |issn=1520-9202 |access-date=2022-12-02 |archive-date=2022-10-31 |archive-url=https://web.archive.org/web/20221031180615/https://ieeexplore.ieee.org/document/9770453/ |url-status=live |url-access=subscription }}</ref> Kinsley and Eric focus on the concepts currently associated with the term where, as Scott Dietzen puts it, "the Web becomes a universal, standards-based integration platform".<ref name="Knorr, Eric 2003"/> In 2004, the term began to popularize 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".<ref name="O'Reilly, Tim 2004">O'Reilly, Tim, and John Battelle. 2004. Opening Welcome: State of the Internet Industry. In San Francisco, California, October 5.</ref> 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 this term with the business models of [[Netscape]] and the [[Encyclopædia Britannica Online]]. For example,

{{blockquote|"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.<ref>O'Reilly, T., 2005.</ref>"}} In short, Netscape focused on creating software, releasing updates and bug fixes, and distributing it to the end users. O'Reilly contrasted this with [[Google]], a company that did not, at the time, focus on producing end-user software, but instead on providing a service based on data, such as the links that Web page authors make between sites. Google exploits this user-generated content to offer Web searches 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]]{{snd}}while the Britannica relies upon experts to write articles and release them periodically in publications, Wikipedia relies on trust in (sometimes anonymous) community members to constantly write and edit content. Wikipedia editors are not required to have educational credentials, such as degrees, in the subjects in which they are editing. Wikipedia is not based on subject-matter expertise, but rather on an adaptation of the [[Open-source software|open source]] software adage [[Linus' Law|"given enough eyeballs, all bugs are shallow"]]. This maxim is stating that if enough users are able to look at a software product's code (or a website), then these users will be able to fix any "[[Bug (computing)|bugs]]" or other problems. The Wikipedia volunteer editor community produces, edits, and updates articles constantly. Web 2.0 conferences have been held every year since 2004, attracting [[entrepreneur]]s, representatives from large companies, tech experts and technology reporters.

The popularity of Web 2.0 was acknowledged by [[You (Time Person of the Year)|2006 ''TIME magazine'' Person of The Year]] (''You'').<ref>Grossman, Lev. 2006. Person of the Year: You. December 25. [http://www.time.com/time/covers/0,16641,20061225,00.html Time.com] {{Webarchive|url=https://web.archive.org/web/20090923143700/http://www.time.com/time/covers/0,16641,20061225,00.html |date=2009-09-23 }}</ref> That is, ''[[Time (magazine)|TIME]]'' selected the masses of users who were participating in content creation on [[social network]]s, blogs, wikis, and media sharing sites.

In the cover story, [[Lev Grossman]] explains:

{{blockquote|"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."}}

====Characteristics====
Instead of merely reading a Web 2.0 site, a user is invited to contribute to the site's content by commenting on published articles, or creating a [[user account]] or [[user profile|profile]] on the site, which may enable increased participation. By increasing emphasis on these already-extant capabilities, they encourage users to rely more on their browser for [[user interface]], [[application software]] ("apps") and [[file storage]] facilities. This has been called "network as platform" computing.<ref name="oreilly" /> Major features of Web 2.0 include [[social networking]] websites, self-publishing platforms (e.g., [[WordPress]]' easy-to-use blog and website creation tools), [[Tag (metadata)|"tagging"]] (which enables users to label websites, videos or photos in some fashion), [[Like button|"like" buttons]] (which enable a user to indicate that they are pleased by online content), and [[social bookmarking]].

Users can provide the data and exercise some control over what they share on a Web 2.0 site.<ref name="oreilly" /><ref name="hinchcliffe">{{cite web
|url=http://web2.wsj2.com/the_state_of_web_20.htm
|title=The State of Web 2.0
|publisher=Web Services
|first = Dion | last = Hinchcliffe
|work=Cloudflare
|date=2006-04-02
|archive-url=https://web.archive.org/web/20070515032339/http://web2.wsj2.com/the_state_of_web_20.htm
|archive-date=2007-05-15
|access-date=2006-08-06
}}</ref> These sites may have an "architecture of participation" that encourages users to add value to the application as they use it.<ref name="graham" /><ref name="oreilly" /> Users can add value in many ways, such as uploading their own content on blogs, consumer-evaluation platforms (e.g. [[Amazon (company)|Amazon]] and [[eBay]]), news websites (e.g. responding in the comment section), social networking services, media-sharing websites (e.g. YouTube and [[Instagram]]) and collaborative-writing projects.<ref>{{Cite journal|last1=Perry|first1=Ronen|last2=Zarsky|first2=Tal|date=2015-08-01|title=Who Should Be Liable for Online Anonymous Defamation?|url=https://papers.ssrn.com/abstract=2671399|language=en|location=Rochester, NY|ssrn=2671399}}</ref> Some scholars argue that [[cloud computing]] is an example of Web 2.0 because it is simply an implication of computing on the Internet.<ref>[SSRN: http://ssrn.com/abstract=732483 {{Webarchive|url=https://web.archive.org/web/20220112052626/https://papers.ssrn.com/sol3/papers.cfm?abstract_id=732483 |date=2022-01-12 }} Wireless Communications and Computing at a Crossroads: New Paradigms and Their Impact on Theories Governing the Public's Right to Spectrum Access], Patrick S. Ryan, Journal on Telecommunications & High Technology Law, Vol. 3, No. 2, p. 239, 2005.</ref> [[File:How to edit a page Edit box.png|thumb|Edit box interface through which anyone could edit a [[Wikipedia]] article]]

Web 2.0 offers almost all users the same freedom to contribute,<ref>{{cite journal |url=https://www.academia.edu/15831013 |title=Learn More About Web 2.0 |publisher=academia.edu |access-date=2015-10-14 |last1=Pal |first1=Surendra Kumar |archive-date=2021-08-14 |archive-url=https://web.archive.org/web/20210814192542/https://www.academia.edu/15831013 |url-status=live }}</ref> which can lead to effects that are varyingly perceived as productive by members of a given community or not, which can lead to emotional distress and disagreement. The impossibility of excluding group members who do not contribute to the provision of goods (i.e., to the creation of a user-generated website) from sharing the benefits (of using the website) gives rise to the possibility that serious members will prefer to withhold their contribution of effort and [[Free rider problem|"free ride"]] on the contributions of others.<ref>Gerald Marwell and Ruth E. Ames: "Experiments on the Provision of Public Goods. I. Resources, Interest, Group Size, and the Free-Rider Problem". ''The American Journal of Sociology'', Vol. 84, No. 6 (May, 1979), pp. 1335–1360
</ref> This requires what is sometimes called [[radical trust]] by the management of the Web site.

[[Encyclopædia Britannica|Encyclopaedia Britannica]] calls [[Wikipedia]] "the epitome of the so-called Web 2.0" and describes what many view as the ideal of a Web 2.0 platform as "an egalitarian environment where the web of social software enmeshes users in both their real and virtual-reality workplaces."<ref>{{Cite web |last1=Hosch |first1=William L. |last2=Tikkanen |first2=Amy |last3=Ray |first3=Michael |last4=Cunningham |first4=John M. |author-link4=John M. Cunningham |last5=Dandrea |first5=Carlos |last6=Gregersen |first6=Erik |last7=Lotha |first7=Gloria |date=2023-04-13 |title=Wikipedia |url=https://www.britannica.com/topic/Wikipedia |access-date=2023-05-11 |publisher=[[Encyclopedia Britannica]] |language=en |archive-date=2022-01-21 |archive-url=https://web.archive.org/web/20220121012545/https://www.britannica.com/topic/Wikipedia |url-status=live }}</ref>
According to Best,<ref>Best, D., 2006. Web 2.0 Next Big Thing or Next Big Internet Bubble? Lecture Web Information Systems. Techni sche Universiteit Eindhoven.</ref> 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,<ref>
{{cite web
|url=http://www.informationweek.com/news/management/showArticle.jhtml;jsessionid=EWRPGLVJ53OW2QSNDLPCKHSCJUNN2JVN?articleID=199702353&_requestid=494050
|title=Amid The Rush To Web 2.0, Some Words Of Warning&nbsp;– Web 2.0&nbsp;– InformationWeek
|publisher=www.informationweek.com
|access-date=2008-04-04
|author1=Greenmeier, Larry
|author2=Gaudin, Sharon
|name-list-style=amp
|archive-url=https://web.archive.org/web/20080421221546/http://www.informationweek.com/news/management/showArticle.jhtml;jsessionid=EWRPGLVJ53OW2QSNDLPCKHSCJUNN2JVN?articleID=199702353&_requestid=494050
|archive-date=2008-04-21
|url-status=live
}}
</ref> and [[collective intelligence]]<ref>O'Reilly, T., 2005. What is Web 2.0. Design Patterns and Business Models for the Next Generation of Software, p. 30</ref> by way of user participation, can also be viewed as essential attributes of Web 2.0. Some websites require users to contribute [[user-generated content]] to have access to the website, to discourage "free riding".[[File:Mass Effect Wiki Collaboration.png|thumb|A list of ways that people can volunteer to improve Mass Effect Wiki on [[Wikia]], an example of content generated by users working collaboratively]]The key features of Web 2.0 include:{{citation needed|date=November 2017}}
# [[Folksonomy]]{{snd}}free classification of information; allows users to collectively classify and find information (e.g. [[Tag (metadata)|"tagging"]] of websites, images, videos or links)
# Rich [[user experience]]{{snd}}dynamic content that is responsive to user input (e.g., a user can "click" on an image to enlarge it or find out more information)
# [[Crowdsourcing|User participation]]{{snd}}information flows two ways between the site owner and site users by means of evaluation, review, and online commenting. Site users also typically create [[user-generated content]] for others to see (e.g., [[Wikipedia]], an online encyclopedia that anyone can write articles for or edit)
# [[Software as a service]] (SaaS){{snd}}Web 2.0 sites developed [[API]]s to allow automated usage, such as by a [[Web app|Web "app"]] ([[software application]]) or a [[mashup (web application hybrid)|mashup]]
# [[Eternal September|Mass participation]]{{snd}}near-universal web access leads to differentiation of concerns, from the traditional Internet user base (who tended to be [[hacker]]s and computer hobbyists) to a wider variety of users, drastically changing the audience of internet users.

==Technologies==
The [[client-side]] ([[Web browser]]) technologies used in Web 2.0 development include [[Ajax (programming)|Ajax]] and [[JavaScript library|JavaScript frameworks]]. Ajax programming uses [[JavaScript]] and the [[Document Object Model]] (DOM) to update selected regions of the page area without undergoing a full page reload. To allow users to continue interacting with the page, communications such as data requests going to the server are separated from data coming back to the page ([[Asynchronous communication|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 the 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 to dynamically update the Web page based on the new data, allowing for 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.

As a widely available plug-in independent of [[W3C]] standards (the World Wide Web Consortium is the governing body of Web standards and protocols), [[Adobe Flash]] was capable of doing many things that were not possible pre-[[HTML5]]. Of Flash's many capabilities, the most commonly used was its ability to integrate streaming multimedia into HTML pages. With the introduction of HTML5 in 2010 and the growing concerns with Flash's security, the role of Flash became obsolete, with browser support ending on December 31, 2020.

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 '[[Software widget|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|server-side]], Web 2.0 uses many of the same technologies as Web 1.0. Languages such as [[Perl]], [[PHP]], [[Python (programming language)|Python]], [[Ruby (programming language)|Ruby]], as well as [[J2EE|Enterprise Java (J2EE)]] and [[.NET Framework|Microsoft.NET Framework]], are used by developers to output data dynamically using information from files and databases. This allows websites and web services to share [[Machine-readable data|machine readable]] formats such as [[XML]] ([[Atom (standard)|Atom]], [[RSS]], etc.) and [[JSON]]. When data is available in one of these formats, another website can use it to [[Mashup (web application hybrid)|integrate a portion of that site's functionality]].

==Concepts==
Web 2.0 can be described in three parts:
* [[Rich web application]]{{snd}}defines the experience brought from desktop to browser, whether it is "rich" from a graphical point of view or a usability/interactivity or features point of view.{{contradictory inline|date=January 2021}}
* [[Web-oriented architecture]] (WOA){{snd}}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 [[Web feed|feeds]], [[RSS feed]]s, [[web services]], [[Mashup (web application hybrid)|mashups]].
* [[Social Web]]{{snd}}defines how Web 2.0 websites tend to interact much more with the end user and make the end user an integral part of the website, either by adding his or her profile, adding comments on content, uploading new content, or adding [[user-generated content]] (e.g., personal [[digital photo]]s).

As such, Web 2.0 draws together the capabilities of [[Client (computing)|client]]- and [[Server (computing)|server]]-side software, [[content syndication]] and the use of [[List of network protocols|network protocols]]. Standards-oriented Web browsers may use [[Plug-in (computing)|plug-ins]] and software extensions to handle the content and user interactions. Web 2.0 sites provide users with [[Computer data storage|information storage]], creation, and dissemination capabilities that were not possible in the environment known as "Web 1.0".

Web 2.0 sites include the following features and techniques, referred to as the acronym [[SLATES]] by Andrew McAfee:<ref>McAfee, A. (2006). Enterprise 2.0: The Dawn of Emergent Collaboration. MIT Sloan Management review. Vol. 47, No. 3, p. 21–28.</ref>

; '''S'''earch
: Finding information through [[keyword search]].
; '''L'''inks to other websites
: Connects information sources together using the model of the Web.
; '''A'''uthoring
: The ability to create and update content leads to the collaborative work of many authors. [[Wiki]] users may extend, undo, redo and edit each other's work. Comment systems allow readers to contribute their viewpoints.
; '''T'''ags
: Categorization of content by users adding "tags"&nbsp;— short, usually one-word or two-word descriptions&nbsp;— to facilitate searching. For example, a user can tag a metal song as "[[death metal]]". Collections of tags created by many users within a single system may be referred to as "folksonomies" (i.e., [[Folk taxonomy|folk]] [[Taxonomy (general)|taxonomies]]).
; '''E'''xtensions
: Software that makes the Web an [[application platform]] as well as a document server. Examples include [[Adobe Reader]], [[Adobe Flash]], [[Microsoft Silverlight]], [[ActiveX]], [[Java programming language|Oracle Java]], [[QuickTime]], [[WPS Office]] and [[Windows Media]].
; Signals
: The use of syndication technology, such as [[RSS]] feeds 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. 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 enterprise uses.<ref>{{cite web|url=http://blogs.zdnet.com/Hinchcliffe/?p=71 |title=Web 2.0 definition updated and Enterprise 2.0 emerges |last=Hinchcliffe |first=Dion |date=November 5, 2006 |website=ZDNet blogs |archive-url=https://web.archive.org/web/20061129225858/http://blogs.zdnet.com/Hinchcliffe/?p=71 |archive-date=2006-11-29}}</ref>

==Social Web==
A third important part of Web 2.0 is the [[social web]]. The social Web consists of a number of online tools and platforms where people share their perspectives, opinions, thoughts and experiences. Web 2.0 applications tend to interact much more with the end user. As such, the end user is not only a user of the application but also a participant by:
* [[Podcasting]]
* [[Blogging]]
* [[Tag (metadata)|Tagging]]
* [[Content curation|Curating]] with [[RSS]]
* [[Social bookmarking]]
* [[Social networking]]
* [[Social media]]
* [[Wiki]]s
* [[Web content voting]]: [[Review site]] or [[Rating site]]

The popularity of the term Web 2.0, along with the increasing use of blogs, wikis, and social networking technologies, has led many in academia and business to append a flurry of 2.0's to existing concepts and fields of study,<ref>Schick, S., 2005. I second that emotion. IT Business.ca (Canada).
</ref> including [[Library 2.0]], Social Work 2.0,<ref>{{cite book
|title=The Role and Regulations for Technology in Social Work Practice and E-Therapy: Social Work 2.0. In A. R. Roberts (Ed).
|last=Singer
|first=Jonathan B.
|year=2009
|publisher=Oxford University Press
|location=New York, U.S.
|isbn=978-0-19-536937-3
|url-access=registration
|url=https://archive.org/details/socialworkersdes0002unse
}}</ref>
[[Enterprise social software|Enterprise 2.0]], PR 2.0,<ref>{{cite book | last=Breakenridge | first=Deirdre |author-link=Deirdre Breakenridge| title=PR 2.0: New Media, New Tools, New Audiences | publisher=Pearson Education | year=2008 | isbn=978-0-13-270397-0}}</ref> Classroom 2.0,<ref>
{{cite web | title = Classroom 2.0 | url = http://www.classroom20.com/ | access-date = 2010-09-22 | archive-url = https://web.archive.org/web/20100922053119/http://www.classroom20.com/ | archive-date = 2010-09-22 | url-status = live }}
</ref> Publishing 2.0,<ref>{{cite web |last=Karp |first=Scott |url=http://publishing2.com/ |title=Publishing 2.0 |publisher=Publishing2.com |access-date=2011-02-06 |archive-url=https://web.archive.org/web/20110206000145/http://publishing2.com/ |archive-date=2011-02-06 |url-status=live }}</ref> Medicine 2.0,<ref>Medicine 2.0</ref> Telco 2.0, Travel 2.0, [[Government 2.0]],<ref>{{cite book
 |url         = http://www.manhattan-institute.org/government2.0/
 |title       = Government 2.0: Using Technology to Improve Education, Cut Red Tape, Reduce Gridlock, and Enhance Democracy
 |last        = Eggers
 |first       = William D.
 |year        = 2005
 |publisher   = Rowman & Littlefield Publishers, Inc.
 |location    = Lanham MD, U.S.
 |isbn        = 978-0-7425-4175-7
 |url-status     = dead
 |archive-url  = https://web.archive.org/web/20090217212239/http://www.manhattan-institute.org/government2.0/
 |archive-date = 2009-02-17
}}</ref> and even [[Porn 2.0]].<ref>{{cite book
|url=http://www.progressiveadvertiser.com/web-2-0-becoming-an-outdated-term/
|archive-url=https://web.archive.org/web/20100303213505/http://www.progressiveadvertiser.com/web-2-0-becoming-an-outdated-term/
|archive-date=March 3, 2010
|title=Web 2.0 Becoming An Outdated Term
|last=Rusak
|first=Sergey
|date=October 1, 2009
|publisher=Progressive Advertiser
|location=Boston, Massachusetts, U.S.
}}</ref> Many of these 2.0s refer to Web 2.0 technologies as the source of the new version in their respective disciplines and areas. For example, in the Talis white paper "Library 2.0: The Challenge of Disruptive Innovation", [[Paul Miller (journalist)|Paul Miller]] argues

<blockquote>"Blogs, wikis and RSS are often held up as exemplary manifestations of Web 2.0. A reader of a blog or a wiki is provided with tools to add a comment or even, in the case of the wiki, to edit the content. This is what we call the Read/Write web. Talis believes that [[Library 2.0]] means harnessing this type of participation so that libraries can benefit from increasingly rich collaborative cataloging efforts, such as including contributions from partner libraries as well as adding rich enhancements, such as book jackets or movie files, to records from publishers and others."<ref>Miller 10–11</ref></blockquote>

Here, Miller links Web 2.0 technologies and the culture of participation that they engender to the field of library science, supporting his claim that there is now a "Library 2.0". Many of the other proponents of new 2.0s mentioned here use similar methods. The meaning of Web 2.0 is role dependent. For example, some use Web 2.0 to establish and maintain relationships through social networks, while some marketing managers might use this promising technology to "end-run traditionally unresponsive I.T. department[s]."<ref>{{cite web |url=http://web2.sys-con.com/node/207411 |title=i-Technology Viewpoint: It's Time to Take the Quotation Marks Off "Web 2.0" &#124; Web 2.0 Journal |publisher=Web2.sys-con.com |access-date=2011-02-06 |archive-url=https://web.archive.org/web/20110216062850/http://web2.sys-con.com/node/207411 |archive-date=2011-02-16 |url-status=live }}</ref>

There is a debate over the use of Web 2.0 technologies in mainstream education. Issues under consideration include the understanding of students' different learning modes; the conflicts between ideas entrenched in informal online communities and educational establishments' views on the production and authentication of 'formal' knowledge; and questions about privacy, plagiarism, shared authorship and the ownership of knowledge and information produced and/or published on line.<ref>{{cite journal |last=Anderson |first=Paul |author-link= |year=2007 |title=What is Web 2.0? Ideas, technologies and implications for education |journal=JISC Technology and Standards Watch |citeseerx=10.1.1.108.9995}}</ref>

===Marketing===
Web 2.0 is used by companies, non-profit organisations and governments for interactive [[marketing]]. A growing number of marketers are using Web 2.0 tools to collaborate with consumers on product development, [[customer service]] enhancement, product or service improvement and promotion. Companies can use Web 2.0 tools to improve collaboration with both its business partners and consumers. Among other things, company employees have created wikis—Websites that allow users to add, delete, and edit content&nbsp;— to list answers to frequently asked questions about each product, and consumers have added significant contributions.

Another marketing Web 2.0 lure is to make sure consumers can use the online community to network among themselves on topics of their own choosing.<ref>
{{cite news | url=https://www.wsj.com/articles/SB122884677205091919 | title=The Secrets of Marketing in a Web 2.0 World | last=Parise | first=Salvatore | newspaper=The Wall Street Journal | date=2008-12-16 | access-date=2017-08-08 | archive-url=https://web.archive.org/web/20170710043624/https://www.wsj.com/articles/SB122884677205091919 | archive-date=2017-07-10 | url-status=live }}
</ref> Mainstream media usage of Web 2.0 is increasing. Saturating media hubs—like ''[[The New York Times]], [[PC Magazine]]'' and ''[[Business Week]]''&nbsp;— with links to popular new Web sites and services, is critical to achieving the threshold for mass adoption of those services.<ref>{{cite web|url=http://www.readwriteweb.com/archives/mainstream_media_web20.php|title=Mainstream Media Usage of Web 2.0 Services is Increasing|last=MacManus|first=Richard|year=2007|publisher=Read Write Web|url-status=dead|archive-url=https://web.archive.org/web/20110811174656/http://www.readwriteweb.com/archives/mainstream_media_web20.php|archive-date=2011-08-11}}</ref> User web content can be used to gauge consumer satisfaction. In a recent article for Bank Technology News, Shane Kite describes how Citigroup's Global Transaction Services unit monitors [[social media]] outlets to address customer issues and improve products.<ref>
{{cite web|url=http://www.pntmarketingservices.com/newsfeed/article/Banks_use_Web_2_0_to_increase_customer_retention-800226524.html|title=Banks use Web 2.0 to increase customer retention|year=2010|publisher=PNT Marketing Services|access-date=2010-11-14|archive-url=https://web.archive.org/web/20101114164314/http://www.pntmarketingservices.com/newsfeed/article/Banks_use_Web_2_0_to_increase_customer_retention-800226524.html|archive-date=2010-11-14|url-status=live}}
</ref>

==== Destination marketing ====
In tourism industries, social media is an effective channel to attract travellers and promote tourism products and services by engaging with customers. The brand of tourist destinations can be built through marketing campaigns on social media and by engaging with customers. For example, the "Snow at First Sight" campaign launched by the [[Colorado|State of Colorado]] aimed to bring brand awareness to Colorado as a winter destination. The campaign used social media platforms, for example, Facebook and Twitter, to promote this competition, and requested the participants to share experiences, pictures and videos on social media platforms. As a result, Colorado enhanced their image as a winter destination and created a campaign worth about $2.9 million.{{citation needed|date=January 2020}}

The tourism organisation can earn brand royalty from interactive marketing campaigns on social media with engaging passive communication tactics. For example, "Moms" advisors of the [[Walt Disney World]] are responsible for offering suggestions and replying to questions about the family trips at Walt Disney World. Due to its characteristic of expertise in Disney, "Moms" was chosen to represent the campaign.<ref name=":0">{{Cite journal|last1=Hudson|first1=Simon|last2=Thal|first2=Karen|date=2013-01-01|title=The Impact of Social Media on the Consumer Decision Process: Implications for Tourism Marketing|journal=Journal of Travel & Tourism Marketing|volume=30|issue=1–2|pages=156–160|doi=10.1080/10548408.2013.751276|s2cid=154791353|issn=1054-8408}}</ref> Social networking sites, such as Facebook, can be used as a platform for providing detailed information about the marketing campaign, as well as real-time online communication with customers. Korean Airline Tour created and maintained a relationship with customers by using Facebook for individual communication purposes.<ref>{{Cite journal|last1=Park|first1=Jongpil|last2=Oh|first2=Ick-Keun|date=2012-01-01|title=A Case Study of Social Media Marketing by Travel Agency: The Salience of Social Media Marketing in the Tourism Industry|journal=International Journal of Tourism Sciences|volume=12|issue=1|pages=93–106|doi=10.1080/15980634.2012.11434654|s2cid=142955027|issn=1598-0634}}</ref>

Travel 2.0 refers a model of Web 2.0 on tourism industries which provides virtual travel communities. The travel 2.0 model allows users to create their own content and exchange their words through globally interactive features on websites.<ref name=":1">{{Cite journal|last1=Buhalis|first1=Dimitrios|last2=Law|first2=Rob|title=Progress in information technology and tourism management: 20 years on and 10 years after the Internet—The state of eTourism research|journal=Tourism Management|language=en|volume=29|issue=4|pages=609–623|doi=10.1016/j.tourman.2008.01.005|year=2008|hdl=10397/527|url=http://eprints.bournemouth.ac.uk/5126/1/TMA_eTourism_20years_Buhalis%26Law_FINAL_.pdf|access-date=2019-12-13|archive-date=2019-08-19|archive-url=https://web.archive.org/web/20190819051415/http://eprints.bournemouth.ac.uk/5126/1/TMA_eTourism_20years_Buhalis%26Law_FINAL_.pdf|url-status=live}}</ref><ref>{{Cite book|title=Information and Communication Technologies in Tourism 2011|last1=Milano|first1=Roberta|last2=Baggio|first2=Rodolfo|last3=Piattelli|first3=Robert|date=2011-01-01|publisher=Springer, Vienna|pages=471–483|language=en|doi=10.1007/978-3-7091-0503-0_38|chapter = The effects of online social media on tourism websites|isbn = 978-3-7091-0502-3|citeseerx = 10.1.1.454.3557|s2cid=18545498 }}</ref> The users also can contribute their experiences, images and suggestions regarding their trips through online travel communities. For example, [[TripAdvisor]] is an online travel community which enables user to rate and share autonomously their reviews and feedback on hotels and tourist destinations. Non pre-associate users can interact socially and communicate through discussion forums on TripAdvisor.<ref name=":2">{{Cite journal|last1=Miguens|first1=J.|last2=Baggio|first2=R.|date=2008|title=Social media and Tourism Destinations: TripAdvisor Case Study|url=http://www.iby.it/turismo/papers/baggio-aveiro2.pdf|journal=Advances in Tourism Research|pages=26–28|access-date=2017-05-10|archive-url=https://web.archive.org/web/20170830003226/http://www.iby.it/turismo/papers/baggio-aveiro2.pdf|archive-date=2017-08-30|url-status=live}}</ref>

Social media, especially Travel 2.0 websites, plays a crucial role in decision-making behaviors of travelers. The user-generated content on social media tools have a significant impact on travelers choices and organisation preferences. Travel 2.0 sparked radical change in receiving information methods for travelers, from business-to-customer marketing into peer-to-peer reviews. User-generated content became a vital tool for helping a number of travelers manage their international travels, especially for first time visitors.<ref name=":3">{{Cite journal|last1=Zeng|first1=Benxiang|last2=Gerritsen|first2=Rolf|date=2014-04-01|title=What do we know about social media in tourism? A review|journal=Tourism Management Perspectives|volume=10|pages=27–36|doi=10.1016/j.tmp.2014.01.001}}</ref> The travellers tend to trust and rely on peer-to-peer reviews and virtual communications on social media rather than the information provided by travel suppliers.<ref name=":2" /><ref name=":0" />

In addition, an autonomous review feature on social media would help travelers reduce risks and uncertainties before the purchasing stages.<ref name=":1" /><ref name=":3" /> Social media is also a channel for customer complaints and negative feedback which can damage images and reputations of organisations and destinations.<ref name=":3" /> For example, a majority of UK travellers read customer reviews before booking hotels, these hotels receiving negative feedback would be refrained by half of customers.<ref name=":3" />

Therefore, the organisations should develop strategic plans to handle and manage the negative feedback on social media. Although the user-generated content and rating systems on social media are out of a business' controls, the business can monitor those conversations and participate in communities to enhance customer loyalty and maintain customer relationships.<ref name=":0" />

==Education==
Web 2.0 could allow for more collaborative education. For example, blogs give students a public space to interact with one another and the content of the class.<ref name=Richardson>{{cite book|last=Richardson|first=Will|title=Blogs, Wikis, Podcasts, and Other Powerful Web Tools for Classrooms|year=2010|publisher=Corwin Press|isbn=978-1-4129-7747-0|page=171}}</ref> Some studies suggest that Web 2.0 can increase the public's understanding of science, which could improve government policy decisions. A 2012 study by researchers at the [[University of Wisconsin–Madison]] notes that

: "...the internet could be a crucial tool in increasing the general public's level of science literacy. This increase could then lead to better communication between researchers and the public, more substantive discussion, and more informed policy decision."<ref name=Ladwig>{{cite journal |author=Pete Ladwig |author2=Kajsa E. Dalrymple |author3=Dominique Brossard |author4=Dietram A. Scheufele |author5=Elizabeth A. Corley |title=Perceived familiarity or factual knowledge? Comparing operationalizations of scientific understanding |journal=Science and Public Policy |volume=39 |issue=6 |year=2012 |pages=761–774 |doi=10.1093/scipol/scs048|doi-access=free }}</ref>
<!-- XXX: The above Richardson source was probably added as an advertisement; if it isn't notable, we should probably remove it entirely. NOTE from second editor: Sources don't have to be notable. See [[WP:Notability]]. Notability on Wikipedia is just used to determine whether a person deserves her own Wikipedia article. Professor Jane Doe may not be Notable (i.e., she may not qualify for her own Wikipedia article), but if she has books published by major, independent publishing houses, we can cite her work on Wikipedia. : ) -->

==Web-based applications and desktops==
[[Ajax (programming)|Ajax]] has prompted the development of Web sites that mimic desktop applications, such as [[word processor|word processing]], the [[spreadsheet]], and [[presentation program|slide-show presentation]]. [[WYSIWYG]] [[wiki]] and [[blog]]ging sites replicate many features of PC authoring applications. Several browser-based services have emerged, including [[EyeOS]]<ref>
{{cite news
|url=https://techcrunch.com/2006/11/27/eyeos-open-source-webos-for-the-masses/
|title=Can eyeOS Succeed Where Desktop.com Failed?
|work=www.techcrunch.com
|access-date=2007-12-12
|archive-url=https://web.archive.org/web/20071212023338/http://www.techcrunch.com/2006/11/27/eyeos-open-source-webos-for-the-masses/
|archive-date=2007-12-12
|url-status=live
}}
</ref> and [[YouOS]].(No longer active.)<ref>
{{cite web
|url=http://www.businessweek.com/the_thread/techbeat/archives/2006/03/hey_youos.html
|title=Tech Beat Hey YouOS!&nbsp;– BusinessWeek
|publisher=www.businessweek.com
|access-date=2007-12-12
|archive-url=https://web.archive.org/web/20071217040221/http://www.businessweek.com/the_thread/techbeat/archives/2006/03/hey_youos.html
|archive-date=2007-12-17
|url-status=dead
}}
</ref> 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.

==Distribution of media==

===XML and RSS===
Many regard syndication of site content as a Web 2.0 feature. Syndication uses standardized protocols to permit end-users to make use of a site's data in another context (such as another Web site, a [[browser plugin]], or a separate desktop application). Protocols permitting syndication include [[RSS (file format)|RSS]] (really simple syndication, also known as Web syndication), [[Resource Description Framework|RDF]] (as in RSS 1.1), and [[Atom (standard)|Atom]], all of which are [[XML]]-based formats. Observers have started to refer to these technologies as [[Web feed]]s.

Specialized protocols such as [[FOAF (software)|FOAF]] and [[XHTML Friends Network|XFN]] (both for social networking) extend the functionality of sites and permit end-users to interact without centralized Web sites.

===Web APIs===
{{Main|Web API}}
Web 2.0 often uses machine-based interactions such as [[Representational State Transfer|REST]] and [[SOAP]]. Servers often expose proprietary [[Application programming interface]]s (APIs), but standard APIs (for example, for posting to a blog or notifying a blog update) have also come into use. Most communications through APIs involve [[XML]] or [[JSON]] payloads. REST APIs, through their use of self-descriptive messages and [[HATEOAS|hypermedia as the engine of application state]], should be self-describing once an entry [[Uniform Resource Identifier|URI]] is known. [[Web Services Description Language]] (WSDL) is the standard way of publishing a SOAP Application programming interface and there are [[List of web service specifications|a range of Web service specifications]].

==Trademark==
In November 2004, [[CMP Media]] applied to the [[United States Patent and Trademark Office|USPTO]] for a [[service mark]] on the use of the term "WEB 2.0" for live events.<ref name="uspto">{{cite web |url=http://tarr.uspto.gov/servlet/tarr?regser=serial&entry=78322306 |title=USPTO serial number 78322306 |publisher=Tarr.uspto.gov |access-date=2011-02-06 |archive-url=https://web.archive.org/web/20110113155427/http://tarr.uspto.gov/servlet/tarr?regser=serial&entry=78322306 |archive-date=2011-01-13 |url-status=live }}</ref> On the basis of this application, CMP Media sent a [[cease and desist|cease-and-desist]] demand to the Irish non-profit organisation IT@Cork on May 24, 2006,<ref>{{cite web |title=O'Reilly and CMP Exercise Trademark on 'Web 2.0' |work=Slashdot |url=http://yro.slashdot.org/article.pl?sid=06/05/26/1238245 |date=2006-05-26 |access-date=2006-05-27 |archive-url=https://web.archive.org/web/20090511040244/http://yro.slashdot.org/article.pl?sid=06%2F05%2F26%2F1238245 |archive-date=2009-05-11 |url-status=live }}</ref> but retracted it two days later.<ref>{{cite web | title=O'Reilly's coverage of Web 2.0 as a service mark | work=O'Reilly Radar | url=http://radar.oreilly.com/archives/2006/05/more_on_our_web_20_service_mar.html | first = Nathan | last = Torkington | date=2006-05-26 | access-date=2006-06-01 |archive-url=https://web.archive.org/web/20080115224430/http://radar.oreilly.com/archives/2006/05/more_on_our_web_20_service_mar.html|archive-date=15 January 2008}}</ref> The "WEB 2.0" service mark registration passed final PTO Examining Attorney review on May 10, 2006, and was registered on June 27, 2006.<ref name="uspto"/> The [[European Union]] application (which would confer unambiguous status in Ireland)<ref>{{cite web|url=https://euipo.europa.eu/eSearch/#details/trademarks/004972212|title=Application number 004972212|year=2007|access-date=2010-03-22|publisher=EUIPO}}</ref> was declined on May 23, 2007.

==Criticism==
Critics of the term claim that "Web 2.0" does not represent a new version of the [[World Wide Web]] at all, but merely continues to use so-called "Web 1.0" technologies and concepts:<ref name="developerWorks Interviews: Tim Berners-Lee" />
* First, techniques such as [[Ajax (programming)|Ajax]] do not replace underlying protocols like [[Hypertext Transfer Protocol|HTTP]], but add a layer of abstraction on top of them.<!--

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* Second, many of the ideas of Web 2.0 were already featured in implementations on networked systems well before the term "Web 2.0" emerged. [[Amazon.com]], for instance, has allowed users to write reviews and consumer guides since its launch in 1995, in a form of self-publishing. Amazon also opened its API to outside developers in 2002.<ref>{{cite web
|title=Amazon Web Services API
|work=O'Reilly Network
|url=http://www.oreillynet.com/pub/wlg/1707?wlg=yes
|author-link=Tim O'Reilly|first=Tim|last=O'Reilly
|date=2002-06-18
|access-date=2006-05-27
|archive-url=https://web.archive.org/web/20060613235806/http://www.oreillynet.com/pub/wlg/1707?wlg=yes
|archive-date=2006-06-13
}}</ref><br>Previous developments also came from research in [[computer-supported collaborative learning]] and [[computer-supported cooperative work]] (CSCW) and from established products like [[Lotus Notes]] and [[Lotus Domino]], all phenomena that preceded Web 2.0. [[Tim Berners-Lee]], who developed the initial technologies of the Web, has been an outspoken critic of the term, while supporting many of the elements associated with it.<ref>{{cite web|url=https://arstechnica.com/business/2006/09/7650/|title=Tim Berners-Lee on Web 2.0: "nobody even knows what it means"|quote=He's big on blogs and wikis, and has nothing but good things to say about AJAX, but Berners-Lee faults the term "Web 2.0" for lacking any coherent meaning.|date=September 2006|access-date=2017-06-15|archive-url=https://web.archive.org/web/20170708091023/https://arstechnica.com/business/2006/09/7650/|archive-date=2017-07-08|url-status=live}}</ref> In [[CERN|the environment where the Web originated]], each workstation had a [[dedicated IP address]] and always-on connection to the Internet. Sharing a file or publishing a web page was as simple as moving the file into a shared folder.<ref>{{cite web|url=http://www.ibm.com/developerworks/podcast/dwi/cm-int082206txt.html|title=developerWorks Interviews: Tim Berners-Lee|website=[[IBM]] |date=2006-08-22|access-date=2007-06-04|archive-url=https://web.archive.org/web/20070701130847/http://www.ibm.com/developerworks/podcast/dwi/cm-int082206txt.html|archive-date=2007-07-01|url-status=live}}</ref><!--

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* Perhaps the most common criticism is that the term is unclear or simply a [[buzzword]].  For many people who work in software, version numbers like 2.0 and 3.0 are for [[software versioning]] or hardware versioning only, and to assign 2.0 arbitrarily to many technologies with a variety of real version numbers has no meaning.  The web does not have a version number.  For example, in a 2006 interview with [[IBM]] developerWorks podcast editor Scott Laningham, Tim Berners-Lee described the term "Web 2.0" as jargon:<ref name="developerWorks Interviews: Tim Berners-Lee">
{{cite web |url=http://www.ibm.com/developerworks/podcast/dwi/cm-int082206txt.html |title=DeveloperWorks Interviews: Tim Berners-Lee |website=[[IBM]] |date=2006-07-28 |access-date=2012-08-05 |archive-url=https://web.archive.org/web/20120821185101/http://www.ibm.com/developerworks/podcast/dwi/cm-int082206txt.html |archive-date=2012-08-21 |url-status=live }}
</ref><blockquote>"Nobody really knows what it means... If Web 2.0 for you is blogs and wikis, then that is people to people. But that was what the Web was supposed to be all along... Web 2.0, for some people, it means moving some of the thinking [to the] client side, so making it more immediate, but the idea of the Web as interaction between people is really what the Web is. That was what it was designed to be... a collaborative space where people can interact."</blockquote><!--

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* Other critics labeled Web 2.0 "a second bubble" (referring to the [[Dot-com bubble]] of 1997–2000), suggesting that too many Web 2.0 companies attempt to develop the same product with a lack of [[business model]]s. For example, ''[[The Economist]]'' has dubbed the mid- to late-2000s focus on Web companies as "Bubble 2.0".<ref>{{cite news |title=Bubble 2.0 |newspaper=The Economist |url=http://www.economist.com/business/displaystory.cfm?story_id=E1_QQNVDDS |date=2005-12-22 |access-date=2006-12-20 |archive-url=https://web.archive.org/web/20061119042722/http://www.economist.com/business/displaystory.cfm?story_id=E1_QQNVDDS |archive-date=2006-11-19 |url-status=live }}</ref>
<!-- ... -->
<!-- I commented this out as it has been proved invalid, actually wrong, due to subsequent events. If someone thinks it should be included with some sort of caveat, do so. Leaving it as is undermines the intent of the section, which is provide valid counter views [[Venture capital]]ist [[Josh Kopelman]] noted that Web 2.0 had excited only 53,651 people (the number of subscribers at that time to [[TechCrunch]], a Weblog covering Web 2.0 startups and technology news), too few users to make them an economically viable target for consumer applications.<ref>{{cite web |title=53,651 |author-link=Josh Kopelman |first=Josh |last=Kopelman |work=Redeye VC |url=http://redeye.firstround.com/2006/05/53651.html |date=2006-05-11 |access-date=2006-12-21 |archive-url=https://web.archive.org/web/20061220220523/http://redeye.firstround.com/2006/05/53651.html |archive-date=2006-12-20 |url-status=live }}</ref> -->
<!-- Critics have cited the language used to describe the hype cycle of Web 2.0<ref>{{cite web |title= Gartner 2006 Emerging Technologies Hype Cycle |url= http://www.gartner.com/it/page.jsp?id=495475 |access-date= 2008-04-07 |archive-url= https://web.archive.org/web/20071029154814/http://www.gartner.com/it/page.jsp?id=495475 |archive-date= 2007-10-29 |url-status= dead }}</ref> as an example of [[Techno-utopianism|Techno-utopianist]] rhetoric.<ref>{{cite web |author-link=Michael Zimmer (academic)|first=Michael|last=Zimmer |title="Critical Perspectives on Web 2.0", Special issue of ''[[First Monday (journal)|First Monday]]'', 13(3), 2008. [http://www.uic.edu/htbin/cgiwrap/bin/ojs/index.php/fm/issue/view/263/showToc UIC.edu]}}</ref> No! This is a misunderstanding of the Gartner Emerging Technologies Hype Cycle! Gartner's concept is applicable to ANY emerging technology. It is isn't a pejorative, or criticism per se, merely an acknowledgment of introduction, gathering momentum, then steady-state which is either success or failure. It doesn't mean that Web 2.0 is "hype". This needs to be reworded or removed. Until then, I have commented it out --><!--

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* In terms of Web 2.0's social impact, critics such as [[Andrew Keen]] argue that Web 2.0 has created a cult of digital [[narcissism]] and amateurism, which undermines the notion of expertise by allowing anybody, anywhere to share and place undue value upon their own opinions about any subject and post any kind of content, regardless of their actual talent, knowledge, credentials, biases or possible hidden agendas. Keen's 2007 book, ''[[Cult of the Amateur]]'', argues that the core assumption of Web 2.0, that all opinions and user-generated content are equally valuable and relevant, is misguided. Additionally, ''[[Sunday Times]]'' reviewer John Flintoff has characterized Web 2.0 as "creating an endless digital forest of mediocrity: uninformed political commentary, unseemly home videos, embarrassingly amateurish music, unreadable poems, essays and novels... [and that Wikipedia is full of] mistakes, half-truths and misunderstandings".<ref>{{cite news | title=Thinking is so over | url=http://technology.timesonline.co.uk/tol/news/tech_and_web/personal_tech/article1874668.ece | location=London | work=The Times | first=JohnPaul | last=Flintoff | date=2007-06-03 | access-date=2009-06-05 | archive-url=https://web.archive.org/web/20090507212657/http://technology.timesonline.co.uk/tol/news/tech_and_web/personal_tech/article1874668.ece | archive-date=2009-05-07 | url-status=dead }}</ref> In a 1994 ''[[Wired (magazine)|Wired]]'' interview, [[Steve Jobs]], forecasting the future development of the web for personal publishing, said:<blockquote>"The Web is great because that person can't foist anything on you—you have to go get it. They can make themselves available, but if nobody wants to look at their site, that's fine. To be honest, most people who have something to say get published now."<ref>{{cite magazine|url=http://archive.wired.com/wired/archive/4.02/jobs_pr.html|title=Steve Jobs: The Next Insanely Great Thing|magazine=Wired|first=Gary|last=Wolf|access-date=2015-04-16|archive-url=https://web.archive.org/web/20150418003143/http://archive.wired.com/wired/archive/4.02/jobs_pr.html|archive-date=2015-04-18|url-status=live}}</ref></blockquote> Michael Gorman, former president of the [[American Library Association]] has been vocal about his opposition to Web 2.0 due to the lack of expertise that it outwardly claims, though he believes that there is hope for the future.:<ref>{{cite web|last=Gorman|first=Michael|title=Web 2.0: The Sleep of Reason, Part 1|url=http://www.britannica.com/blogs/2007/06/web-20-the-sleep-of-reason-part-i/|access-date=26 April 2011|archive-url=https://web.archive.org/web/20110629070412/http://www.britannica.com/blogs/2007/06/web-20-the-sleep-of-reason-part-i/|archive-date=29 June 2011|url-status=live|df=dmy-all}}</ref><blockquote>"The task before us is to extend into the digital world the virtues of authenticity, expertise, and scholarly apparatus that have evolved over the 500 years of print, virtues often absent in the manuscript age that preceded print".</blockquote><!--

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* There is also a growing body of critique of Web 2.0 from the perspective of [[political economy]]. Since, as Tim O'Reilly and John Batelle put it, Web 2.0 is based on the "customers... building your business for you,"<ref name="O'Reilly, Tim 2004"/> critics have argued that sites such as Google, Facebook, YouTube, and Twitter are exploiting the "free labor"<ref>{{cite journal|last=Terranova|first=Tiziana|title=Free Labor: Producing Culture for the Digital Economy|journal=Social Text|year=2000|volume=18|issue=2|pages=33–58|doi=10.1215/01642472-18-2_63-33|s2cid=153872482}}</ref> of user-created content.<ref>{{cite journal|last=Peterson|first=Soren|title=Loser Generated Content: From Participation to Exploitation|journal=First Monday|year=2008|volume=13|issue=3|url=http://firstmonday.org/htbin/cgiwrap/bin/ojs/index.php/fm/article/view/2141/1948|access-date=2012-04-28|archive-url=https://web.archive.org/web/20121025111135/http://firstmonday.org/htbin/cgiwrap/bin/ojs/index.php/fm/article/view/2141/1948|archive-date=2012-10-25|url-status=live}} {{cite book|last=Taylor|first=Astra|title=The People's Platform: Taking Back Power and Culture in the Digital Age|publisher=Metropolitan Books|year=2014|isbn=9780805093568}}</ref> Web 2.0 sites use Terms of Service agreements to claim perpetual licenses to user-generated content, and they use that content to create profiles of users to sell to marketers.<ref>{{cite journal|last=Gehl|first=Robert|title=The Archive and the Processor: The Internal Logic of Web 2.0|journal=New Media and Society|year=2011|volume=13|issue=8|pages=1228–1244|doi=10.1177/1461444811401735|s2cid=38776985}}</ref> This is part of increased surveillance of user activity happening within Web 2.0 sites.<ref>{{cite book|last=Andrejevic|first=Mark|title=iSpy: Surveillance and Power in the Interactive Era|year=2007|publisher=U P of Kansas|location=Lawrence, KS|isbn=978-0-7006-1528-5}}</ref> Jonathan Zittrain of Harvard's Berkman Center for the Internet and Society argues that such data can be used by governments who want to monitor dissident citizens.<ref>{{cite web|last=Zittrain|first=Jonathan|title=Minds for Sale|url=http://cyber.law.harvard.edu/interactive/events/2009/11/berkwest|publisher=Berkman Center for the Internet and Society|access-date=13 April 2012|archive-url=https://web.archive.org/web/20111112061331/http://cyber.law.harvard.edu/interactive/events/2009/11/berkwest|archive-date=12 November 2011|url-status=live|df=dmy-all}}</ref> The rise of [[AJAX]]-driven web sites where much of the content must be rendered on the client has meant that users of older hardware are given worse performance versus a site purely composed of HTML, where the processing takes place on the server.<ref>{{cite web|url=http://www.ibm.com/developerworks/library/wa-aj-web20/|title=Accessibility in Web 2.0 technology|website=[[IBM]] |quote=In the Web application domain, making static Web pages accessible is relatively easy. But for Web 2.0 technology, dynamic content and fancy visual effects can make accessibility testing very difficult.|access-date=2014-09-15|archive-url=https://web.archive.org/web/20150402110510/http://www.ibm.com/developerworks/library/wa-aj-web20/|archive-date=2015-04-02|url-status=live}}</ref> [[Accessibility]] for disabled or impaired users may also suffer in a Web 2.0 site.<ref>{{cite web|url=http://www.sfsu.edu/access/webaccess/webtwo.html|title=Web 2.0 and Accessibility|archive-url=https://web.archive.org/web/20140824234544/http://www.sfsu.edu/access/webaccess/webtwo.html|archive-date=24 August 2014|quote=Web 2.0 applications or websites are often very difficult to control by users with assistive technology.}}</ref><!--

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* Others have noted that Web 2.0 technologies are tied to particular political ideologies. "Web 2.0 discourse is a conduit for the materialization of neoliberal ideology."<ref>{{cite journal|last=Marwick|first=Alice|title=Status Update: Celebrity, publicity and Self-Branding in Web 2.0|year=2010|url=http://www.tiara.org/blog/wp-content/uploads/2010/09/marwick_dissertation_statusupdate.pdf|access-date=2017-07-06|archive-url=https://web.archive.org/web/20170722122938/http://www.tiara.org/blog/wp-content/uploads/2010/09/marwick_dissertation_statusupdate.pdf|archive-date=2017-07-22|url-status=live}}</ref>  The technologies of Web 2.0 may also "function as a disciplining technology within the framework of a neoliberal political economy."<ref>{{cite journal|last=Jarrett|first=Kylie|title=Interactivity Is Evil! A Critical Investigation of Web 2.0|journal=First Monday|year=2008|volume=13|issue=3|doi=10.5210/fm.v13i3.2140|url=http://eprints.maynoothuniversity.ie/4580/1/KJ_Interactivity_Evil.pdf|access-date=2019-12-13|archive-date=2017-11-03|archive-url=https://web.archive.org/web/20171103063733/http://eprints.maynoothuniversity.ie/4580/1/KJ_Interactivity_Evil.pdf|url-status=live |doi-access=free }}</ref><!--

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* When looking at Web 2.0 from a cultural convergence view, according to Henry Jenkins,<ref>{{cite journal |last1=Jenkins |first1=Henry |title=Convergence Culture |journal=The International Journal of Research into New Media Technologies |date=2008 |volume=14 |issue=1 |pages=5–12 |doi=10.1177/1354856507084415 |doi-access=free }}</ref> it can be problematic because the consumers are doing more and more work in order to entertain themselves. For instance, Twitter offers online tools for users to create their own tweet, in a way the users are doing all the work when it comes to producing media content.

==See also==
{{div col|colwidth=20em}}
* [[Cloud computing]]
* [[Collective intelligence]]
* [[Connectivity (media)|Connectivity]] of social media
* [[Crowd computing]]
* [[Cute cat theory of digital activism]]
* [[Enterprise social software]]
* [[Libraries in virtual worlds]]
* [[List of free and open-source web applications]]
* [[Mass collaboration]]
* [[New media]]
* [[Office suite]]
* [[Open-source governance]]
* [[Privacy concerns with social networking services]]
* [[Responsive web design]]
* [[Semantic Web]], sometimes called Web 3.0
* [[Social commerce]]
* [[Social shopping]]
* [[Web 2.0 for development]] (web2fordev)
* [[Web3]]
* [[You (Time Person of the Year)]]
{{div col end}}

; Application domains
{{div col|colwidth=20em}}
* [[Sci-Mate]]
* [[Business 2.0]]
* [[Learning 2.0|E-learning 2.0]]
* [[e-government]] (Government 2.0)
* [[Health 2.0]]
* [[Science 2.0]]
{{div col end}}

==References==
{{Reflist}}

==External links==
{{commons category}}
* {{Wikiversity inline}}
{{Scholia}}
* {{cite book | title=Web 2.0 / Social Media / Social Networks|year=2017| publisher=MultiMedia| location=Charleston, South Carolina, SUA| isbn=978-1-544-63831-7}}

{{Semantic Web}}

[[Category:Web 2.0| ]]
[[Category:2000s in computing]]
[[Category:Brand management]]
[[Category:Cloud applications]]
[[Category:Internet ages]]
[[Category:Internet culture]]
[[Category:New media]]
[[Category:Social information processing]]
[[Category:Technology neologisms]]
[[Category:Web 2.0 neologisms| ]]
[[Category:Web services]]
[[Category:1999 neologisms]]
[[Category:1990s in computing]]