Technologies:
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.
On the server side, Web 2.0 uses many of the same technologies as Web 1.0. New Languages such as PHP, Ruby, ColdFusion, Perl, Python, JSP and ASP are used by developers to dynamically output data using information from files and databases. What has begun to change in Web 2.0 is the way this data is formatted.
What has begun to change in Web 2.0 is the way this data is formatted and share data.
To share its data with other sites, a web site must be able to generate output in machine-readable formats such as XML, RSS, and JSON.
Concepts:
Web 2.0 draws together the capabilities of client-side 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.
Web 2.0 websites typically include some of the following features and techniques:
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".
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.
