Web 2.0 31
Web-based applications and desktops
Ajax has prompted the development of websites that mimic desktop applications, such as word processing, the
spreadsheet, and slide-show presentation. In 2006 Google, Inc. acquired one of the best-known sites of this broad
class, Writely.[48] WYSIWYG wiki and blogging sites replicate many features of PC authoring applications.
Several browser-based "operating systems" have emerged, including EyeOS[49] and YouOS.(No longer active.)[50]
Although coined as such, many of these services function less like a traditional operating system and more as an
application platform. They mimic the user experience of desktop operating-systems, offering features and
applications similar to a PC environment, and are able to run within any modern browser. However, these so-called
"operating systems" do not directly control the hardware on the client's computer.
Numerous web-based application services appeared during the dot-com bubble of 1997–2001 and then vanished,
having failed to gain a critical mass of customers. In 2005, WebEx acquired one of the better-known of these,
Intranets.com, for $45 million.[51]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 website, a browser plugin, or a separate
desktop application). Protocols permitting syndication include RSS (really simple syndication, also known as web
syndication), RDF (as in RSS 1.1), and Atom, all of them XML-based formats. Observers have started to refer to
these technologies as web feeds.
Specialized protocols such as FOAF and XFN (both for social networking) extend the functionality of sites or permit
end-users to interact without centralized websites.Web APIs
Web 2.0 often uses machine-based interactions such as REST and SOAP. Servers often expose proprietary
Application programming interfaces (API), 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 hypermedia as the engine of application state, should
be self-describing once an entry URI is known. Web Services Description Language (WSDL) is the standard way of
publishing a SOAP API and there are a range of web service specifications. EMML, or Enterprise Mashup Markup
Language by the Open Mashup Alliance, is an XML markup language for creating enterprise mashups.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. First, techniques such as AJAX do not replace
underlying protocols like HTTP, but add an additional layer of abstraction on top of them. Second, many of the ideas
of Web 2.0 had already been 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.[52] 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.
But perhaps the most common criticism is that the term is unclear or simply a buzzword. For example, in a podcast
interview,[4] Tim Berners-Lee described the term "Web 2.0" as a "piece of jargon":