Definition of Web 2.0

The term Web 2.0 became popular since its was used in 2004 to designate the O'Reilly Web 2.0 conference. The theme was devoted to sites that had survived the Internet bubble burst in 2001, and what they might have in common.

Tim O'Reilly defined it as follows:

"Web 2.0 is the business revolution in the computer industry caused by the move to the Internet as platform, and an attempt to understand the rules for success on that new platform."

The word has been more precisely defined in an article published on September 30 2005 on the site of the O'Reilly publisher, What is Web 2.0?

A website becomes 2.0 when the webmaster can concentrate on the content using a CMS, when it includes Web services, the collaboration of Internet users contributes to the development of the site or form the main content of the site, and has a social impact.

The definition was developed in the article as a series of technical innovations and social effects.

The combination of web services, the mashup, using multiple API to create innovative new services is another aspect of Web 2.0.
The simplest example is the linking of a database of a real estate agency with Google Maps and Street View to locate a home and show its environment.

The Web as a platform

In the previous Web 1.0, the product is the application. Netscape Browser was an example. It is a tool for the Web, and a program as another. In contrast services that Google offers such as Adsense, Gmail, all use the Web as a platform: there are not software running on the Web, there are a set of services based on the Web. For Google, the Web is a space in which the user is immersed inside different services while Netscape is just a product running on the Web.
The Web 2.0 takes advantage of the "long trail", the collective strength of a multitude of small sites became participants while previously that had only access to it.

The lesson is the need to develop a simple access service and an algorithmic data management to reach the entire Web.

The collective strength

And if hyperlinks, the foundation of the Web become as the synapses of a giant digital brain? Google uses them to determine the value of a site with its PageRank. eBay creates an economy of resale that exists only by the activity of a multitude of players, that can work only with a very large number of actors.
Amazon, asking webmasters to promote and criticism its products, (the same products as its competitors), has also became a very huge company with only
Wikis are also sites created by users and Wikipedia demonstrates the importance they may have. Similarly digg-likes that make use of tagging from users and sharing websites as Flickr, Youtube, Dailymotion.
This is called viral marketing when so promoting a site is maintained by a large numbers of users.
This same phenomenon of group production is the basis of open source software such as Linux, Apache, MySQL, PHP, which operate most of the Web!

In conclusion, this is involvement of users and their contribution in the network that makes it a success.

The spread of information and the blogosphere

The management of news and its spread in real time is another aspect of Web 2.0. The blogs are the vector, and the technical means is given by RSS.
The proliferation of blogs, hosted on a community website or built on his own website with a CMS (Content Management System) as Wordpress is an aspect of the Web 2.0.
RSS files displayed on pages of sites or on users' desktops are updated in line with the news, that so has moved from the television to the computer.
Blogging establish permalinks, links between blog, reciprocal links, which form communities, social networks and will give life to our giant digital brain based on links.
Permalinks amplify the PageRank in the field of news and create a phenomenon whose relevance is limited in time.

Everything is in the data

The basis of all important sites on the web 2.0 is in the data. The content of the sites for search engines, Google Maps for geography, customers for eBay, and so on. This gives SQL same importance as HTML.
In the modern Web data can be combined with services through mashups.
An example is the combination of geographical data from Maps with a real estate file to provide a photographic vision an offer of housing.
Thus, the possession of data is becoming a major stake and a threat to personal safety.
Following the example of open source software, Free Data are promoted by the Common Creative Licensing and the GreaseMonkey project.

A new programming model

Decentralization and popularization of programming tasks promotes the use of scripting languages such as JavaScript, PHP, Ruby, Python, Go.
It has also spawned a proliferation of frameworks, including Ajax frameworks to power dynamic websites.
The programming model is needed lightweight and it is based on Ajax for exchange of data and on REST for Web services.
In addition comes the use of rich interfaces with either HTML 5 or XAML on Windows 8, Android, Qt (QML), JavaFX.
The model also becomes reactive and quickly adapts to the needs of users.

Innovations of the Web 2.0 and the future

Mashup

It is a hybrid Web application giving access to various Web services starting from a single webpage.
Technically, that consists for the Webmaster in incorporating on his site, source codes provided by various actors on the Web such as Google, Yahoo, etc.
It is not a question of a simple accumulation of gadgets: the services can be combined to create something new.
An example:
- For a part, Google Maps which provides the detailed chart of a city.
- In addition a real service giving access to an empty list of residences.
The combination of both makes it possible to physically see the available residences on the map.
That also functions for restaurants, shops, any trade or even any tourist place.

The semantic Web

It is a project to create a universal support for exchange of information while placing on the Web documents which can be treated by computers. Semantics means that the processing takes into account the meaning of the contents of the documents. The project develops the Web by standards like markup languages (XFN, RSS) and specialized tools for the processing.
In fact this innovation contains a traditional part, the formats, and a part under development, the tools to make an intelligent processing of information through these formats.

Rich Internet Applications (RIA)

In other words applications equipped with complete graphic interfaces and processing functionalities identical to those of desktop applications.
They are built using frameworks, in Javascript client-side (on the navigator) and generally support Ajax for the interaction with the server.

The characteristic of Web applications and what differentiates them from local applications, in addition to the fact that there is generally nothing to install on its computer, is the collaborative aspect. The possibility of making multiple actors working together and making them collaborate in the construction of a project.
The Second Life webiste, which proposes a virtual existence to you, is a good example of application using all the resources of Web 2.0. Companies as Reuters now do open agencies in this virtual world, which is an original means of promotion.

What will come next Web 2.0?

The Chrome Google browser wants to further accelerate the transformation of the Internet by making the browser a platform to applications, which may in the future replace the operating system. This is the step next to 2.0.

The popularization of smartphones with applications and connected to the Web will accentuate its role as service provider. Sites will becomes applications or backends for third-party applications. This is already true for Facebook which is a both a platform and a site with a builtin service.