1. WEB 2.0
Name of presentation
by Mr R.RAJAVEL
(MAGNA COLLEGE OF ENGINEERING) Page 1

2. The term "Web 2.0" is commonly associated with web applications that
facilitate interactive information sharing, interoperability,
user-centered design,[1] and collaboration on the World Wide Web. A
Web 2.0 site allows its users to interact with each other as contributors to
the website's content, in contrast to websites where users are limited to
the passive viewing of information that is provided to them. Examples of
Web 2.0 include web-based communities, hosted services,
web applications, social-networking sites, video-sharing sites, wikis, blogs
, mashups, and folksonomies.
The term is closely associated with Tim O'Reilly because of the
O'Reilly Media Web 2.0 conference in 2004.[2][3] Although the term
suggests a new version of the World Wide Web, it does not refer to an
update to any technical specifications, but rather to cumulative changes
in the ways software developers and end-users use the Web. Whether
Web 2.0 is qualitatively different from prior web technologies has been
challenged by World Wide Web inventor Tim Berners-Lee, who called the
term a "piece of jargon"[4] — precisely because he specifically intended
the Web to embody these values in the first place.
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3. History:
The term "Web 2.0" was coined in 1999 by Darcy DiNucci. In her article, "Fragmented Future," DiNucci
writes:[5]
The Web we know now, which loads into a browser window in essentially static screenfulls, 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 screenfulls 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.
Her use of the term deals mainly with Web design and aesthetics; she argues that the Web is "fragmenting"
due to the widespread use of portable Web-ready devices. Her article is aimed at designers, reminding
them to code for an ever-increasing variety of hardware. As such, her use of the term hints at – but does
not directly relate to – the current uses of the term.
The term did not resurface until 2003.[6][7][8] These authors focus on the concepts currently associated
with the term where, as Scott Dietzen puts it, "the Web becomes a universal, standards-based integration
platform".[9]
In 2004, the term began its rise in popularity when O'Reilly Media and MediaLive hosted the first Web 2.0
conference. In their opening remarks, John Battelle and Tim O'Reilly outlined their definition of the "Web as
Platform", where software applications are built upon the Web as opposed to upon the desktop. The unique
aspect of this migration, they argued, is that "customers are building your business for you".[10] They
argued that the activities of users generating content (in the form of ideas, text, videos, or pictures) could be
"harnessed" to create value. Page 3

4. 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.[11]
In short, Netscape focused on creating software, updating it on occasion, and distributing
it to the end users. O'Reilly contrasted this with Google, a company which did not at the
time focus on producing software, such as a browser, but instead focused on providing a
service based on data. The data being the links Web page authors make between sites.
Google exploits this user-generated content to offer Web search based on reputation
through its "page rank" 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 Encyclopedia Britannica Online and
Wikipedia: while the Britannica relies upon experts to create articles and releases them
periodically in publications, Wikipedia relies on trust in anonymous users to constantly and
quickly build content. Wikipedia is not based on expertise but rather an adaptation of the
open source software adage "given enough eyeballs, all bugs are shallow", and it
produces and updates articles constantly. Page 4

5. Characteristics
Flickr, a Web 2.0 web site that allows its users to upload and share photos
Web 2.0 websites allow users to do more than just retrieve information. They can build on
the interactive facilities of "Web 1.0" to provide "Network as platform" computing, allowing
users to run software-applications entirely through a browser.[3] Users can own the data
on a Web 2.0 site and exercise control over that data.[3][14] These sites may have an
"Architecture of participation" that encourages users to add value to the application as
they use it.[2][3]
The concept of Web-as-participation-platform captures many of these characteristics. Bart
Decrem, a founder and former CEO of Flock, calls Web 2.0 the "participatory Web"[15]
and regards the Web-as-information-source as Web 1.0.
The impossibility of excluding group-members who don’t contribute to the provision of
goods from sharing profits gives rise to the possibility that rational members will prefer to
withhold their contribution of effort and free-ride on the contribution of others.[16] This
requires what is sometimes called Radical Trust by the management of the website.
According to Best,[17] 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[18] and collective intelligence[19] by way of
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user participation, can also be viewed as essential attributes of Web 2.0.

6. Technology overview
Web 2.0 draws together the capabilities of client- and server-
side software, content syndication and the use of
network protocols. Standards-oriented web browsers may use
plug-ins and software extensions to handle the content and
the user interactions. Web 2.0 sites provide users with
information storage, creation, and dissemination capabilities
that were not possible in the environment now known as "Web
1.0".
Web 2.0 websites typically include some of the following
features and techniques. Andrew McAfee used the acronym
SLATES to refer to them:[20]
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7. Search: Finding information through keyword search.
Links: Connects information together into a meaningful information ecosystem using the model of the Web, and
provides low-barrier social tools.
Authoring: The ability to create and update content leads to the collaborative work of many rather than just a few
web authors. In wikis, users may extend, undo and redo each other's work. In blogs, posts and the comments of
individuals build up over time.
Tags: Categorization of content by users adding "tags" - short, usually one-word descriptions - to facilitate
searching, without dependence on pre-made categories. Collections of tags created by many users within a single
system may be referred to as "folksonomies" (i.e., folk taxonomies).
Extensions: Software that makes the Web an application platform as well as a document server.
Signals: The use of syndication technology such as RSS to notify users of content changes.
While SLATES forms the basic framework of Enterprise 2.0, it does not contradict all of the higher level Web 2.0
design patterns and business models. And in this way, the new Web 2.0 report from O'Reilly is quite effective and
diligent in interweaving the story of Web 2.0 with the specific aspects of Enterprise 2.0. It includes discussions of
self-service IT, the long tail of enterprise IT demand, and many other consequences of the Web 2.0 era in the
enterprise. The report also makes many sensible recommendations around starting small with pilot projects and
measuring results, among a fairly long list. [21]
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8. How it works
The client-side/web browser technologies typically used in Web 2.0 development are Asynchronous
JavaScript and XML (Ajax), Adobe Flash and the Adobe Flex framework, and JavaScript/Ajax
frameworks such as Yahoo! UI Library, Dojo Toolkit, MooTools, and jQuery. Ajax programming uses
JavaScript to upload and download new data from the web server without undergoing a full page
reload.
To permit the user to continue to interact with the page, communications such as data requests going
to the server are separated from data coming back to the page (asynchronously). Otherwise, the user
would have to routinely wait for the data to come back before they can do anything else on that page,
just as a user has to wait for a page to complete the reload. This also increases overall performance
of the site, as the sending of requests can complete quicker independent of blocking and queueing
required to send data back to the client.
The data fetched by an Ajax request is typically formatted in XML or JSON (JavaScript Object
Notation) format, two widely used structured data formats. Since both of these formats are natively
understood by JavaScript, a programmer can easily use them to transmit structured data in their web
application. When this data is received via Ajax, the JavaScript program then uses the
Document Object Model (DOM) to dynamically update the web page based on the new data, allowing
for a rapid and interactive user experience. In short, using these techniques, Web designers can
make their pages function like desktop applications. For example, Google Docs uses this technique
to create a Web-based word processor.
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9. Usage
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 coin a flurry of 2.0s,[23]
including Library 2.0,[24] Social Work 2.0,[25] Enterprise 2.0, PR 2.0,[26] Classroom 2.0, Publishing
2.0, Medicine 2.0, Telco 2.0, Travel 2.0, Government 2.0,[27] and even Porn 2.0.[28] 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 argues
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 cataloguing 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.[29]
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.
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10. ATOM
The name Atom applies to a pair of related standards. The Atom Syndication Format is an
XML language used for web feeds, while the Atom Publishing Protocol (AtomPub or APP)
is a simple HTTP-based protocol for creating and updating web resources.
Web feeds allow software programs to check for updates published on a website. To
provide a web feed, a site owner may use specialized software (such as a
content management system) that publishes a list (or "feed") of recent articles or content
in a standardized, machine-readable format. The feed can then be downloaded by
websites that syndicate content from the feed, or by feed reader programs that allow
Internet users to subscribe to feeds and view their content.
A feed contains entries, which may be headlines, full-text articles, excerpts, summaries,
and/or links to content on a website, along with various metadata.
The Atom format was developed as an alternative to RSS. Ben Trott, an advocate of the
new format that became Atom, believed that RSS had limitations and flaws—such as lack
of on-going innovation and its necessity to remain backward compatible— and that there
were advantages to a fresh design.[1]
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11. Usage
Web feeds are used by the blogging community to share recent entries' headlines, full text, and even
attached multimedia files.[2] These providers allow other websites to incorporate the blog's
"syndicated" headline or headline-and-short-summary feeds under various usage agreements. Atom
and other web syndication formats are now used for many purposes, including journalism, marketing,
bug-reports, or any other activity involving periodic updates or publications. Atom also provides a
standard way to export an entire blog, or parts of it, for backup or for importing into other blogging
systems.
It is common to find web feeds on major Web sites, as well as many smaller ones. Some websites let
people choose between RSS or Atom formatted web feeds; others offer only RSS or only Atom. In
particular, many blog and wiki sites offer their web feeds in the Atom format.
A feed reader or "aggregator" program can be used to check feeds and display new articles.
Client-side readers may also be designed as standalone programs or as extensions to existing
programs like web browsers. Browsers are moving toward integrated feed reader functions.
Web-based feed readers and news aggregators require no software installation and make the user's
"feeds" available on any computer with Web access. Some aggregators syndicate (combine) web
feeds into new feeds, e.g., taking all football related items from several sports feeds and providing a
new football feed. There are also several search engines for web feed content[citation needed].
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12. RSS
RSS (most commonly expanded as Really Simple Syndication) is a family of web feed formats used
to publish frequently updated works—such as blog entries, news headlines, audio, and video—in a
standardized format.[2] An RSS document (which is called a "feed", "web feed",[3] or "channel")
includes full or summarized text, plus metadata such as publishing dates and authorship. Web feeds
benefit publishers by letting them syndicate content automatically. They benefit readers who want to
subscribe to timely updates from favored websites or to aggregate feeds from many sites into one
place. RSS feeds can be read using software called an "RSS reader", "feed reader", or "aggregator",
which can be web-based, desktop-based, or mobile-device-based. A standardized XML file format
allows the information to be published once and viewed by many different programs. The user
subscribes to a feed by entering into the reader the feed's URI or by clicking an RSS icon in a web
browser that initiates the subscription process. The RSS reader checks the user's subscribed feeds
regularly for new work, downloads any updates that it finds, and provides a user interface to monitor
and read the feeds.
RSS formats are specified using XML, a generic specification for the creation of data formats.
Although RSS formats have evolved from as early as March 1999,[4] it was between 2005 and 2006
when RSS gained widespread use, and the ("") icon was decided upon by several major Web
browsers.[5]
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13. History
Main article: History of web syndication technology
The RSS formats were preceded by several attempts at web syndication that did not achieve
widespread popularity. The basic idea of restructuring information about websites goes back to as
early as 1995, when Ramanathan V. Guha and others in Apple Computer's
Advanced Technology Group developed the Meta Content Framework.[6] For a more detailed
discussion of these early developments, see the history of web syndication technology.
RDF Site Summary, the first version of RSS, was created by Guha at Netscape in March 1999 for use
on the My.Netscape.Com portal. This version became known as RSS 0.9.[4] In July 1999, Dan Libby
of Netscape produced a new version, RSS 0.91,[2] which simplified the format by removing RDF
elements and incorporating elements from Dave Winer's scriptingNews syndication format.[7] Libby
also renamed RSS "Rich Site Summary" and outlined further development of the format in a "futures
document".[8]
This would be Netscape's last participation in RSS development for eight years. As RSS was being
embraced by web publishers who wanted their feeds to be used on My.Netscape.Com and other early
RSS portals, Netscape dropped RSS support from My.Netscape.Com in April 2001 during new owner
AOL's restructuring of the company, also removing documentation and tools that supported the
format.[9]
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14. Variants
There are several different versions of RSS, falling into two major branches (RDF and 2.*).
The RDF (or RSS 1.*) branch includes the following versions:
RSS 0.90 was the original Netscape RSS version. This RSS was called RDF Site Summary, but was based on an
early working draft of the RDF standard, and was not compatible with the final RDF Recommendation.
RSS 1.0 is an open format by the RSS-DEV Working Group, again standing for RDF Site Summary. RSS 1.0 is an
RDF format like RSS 0.90, but not fully compatible with it, since 1.0 is based on the final RDF 1.0
Recommendation.
RSS 1.1 is also an open format and is intended to update and replace RSS 1.0. The specification is an
independent draft not supported or endorsed in any way by the RSS-Dev Working Group or any other organization.
The RSS 2.* branch (initially UserLand, now Harvard) includes the following versions:
RSS 0.91 is the simplified RSS version released by Netscape, and also the version number of the simplified version
originally championed by Dave Winer from Userland Software. The Netscape version was now called Rich Site
Summary; this was no longer an RDF format, but was relatively easy to use.
RSS 0.92 through 0.94 are expansions of the RSS 0.91 format, which are mostly compatible with each other and
with Winer's version of RSS 0.91, but are not compatible with RSS 0.90.
RSS 2.0.1 has the internal version number 2.0. RSS 2.0.1 was proclaimed to be "frozen", but still updated shortly
after release without changing the version number. RSS now stood for Really Simple Syndication. The major 14
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change in this version is an explicit extension mechanism using XML namespaces.[21]

15. Modules
The primary objective of all RSS modules is to extend the basic XML
schema established for more robust syndication of content. This
inherently allows for more diverse, yet standardized, transactions without
modifying the core RSS specification.
To accomplish this extension, a tightly controlled vocabulary (in the RSS
world, "module"; in the XML world, "schema") is declared through an
XML namespace to give names to concepts and relationships between
those concepts.
Some RSS 2.0 modules with established namespaces are:
Ecommerce RSS 2.0 Module
Media RSS 2.0 Module
OpenSearch RSS 2.0 Module Page 15