What is Joomla?
Joomla is an award-winning content management system (CMS), which enables you
to build Web sites and powerful online applications. Many aspects, including its ease-of-use and extensibility, have made Joomla the most popular website software available. Best of all, Joomla is an open source solution that is freely available to everyone.

Joomla is used all over the world to power Web sites of all shapes and sizes :

• Corporate Web sites or portals
• Corporate intranets and extranets
• Online magazines, newspapers, and publications
• E-commerce and online reservations
• Government applications
• Small business Web sites
• Community-based portals
• Non-profit and organizational Web sites
• School and church Web sites
• Personal or family homepages

Who uses joomla ?

• MTV Networks Quizilla (Social networking) - http://www.quizilla.com
• IHOP (Restaurant chain) – http://www.ihop.com
• Harvard University (Educational) – http://gsas.harvard.edu
• Citibank (Financial institution intranet) – Not publicly accessible
• The Green Maven (Eco-resources) www.greenmaven.com
• Outdoor Photographer (Magazine)www.outdoorphotographer.com
• PlayShakespeare.com (Cultural)   www.playshakespeare.com
• Senso Interiors (Furniture design) www.sensointeriors.co.za
• United nations regional information centre www.unric.org/
• More examples of companies using Joomla can be found in the Joomla Community Site Showcase.

Joomla popularity

joomla features

• Contact Management
• Web Link Management
• Content Management
• Syndication and Newsfeed Management
• Menu Manager
• Template Management
• Integrated Help System
• Web Services
• Powerful Extensibility

Joomla help and support

Online help and support are easily found online.  Joomla has support for all kinds of users including: content editors, designers, and developers .

www.joomla.com has everything you need .

Also there are numerous books that help you use, develop and master the joomla cms .

Joomla development

• Joomla development is very organized utilizing three development teams: development, a bug squad, and security.
• The joomla development cycle relies on the community feedback.
• The joomla development team is supported  by the open source matter organization, ensuring the continual development of joomla.

joomla extensions

A Joomla! extension is anything that extends Joomla!’s functionality beyond the core. There are three main types of extension: components, modules, and plugins.

To view the extension directory, visit http://extensions.joomla.org/extensions/

Extension Types

• Modules – Typically make up the elements of a sidebar or content menus. Modules complement the content contained in a component; they are not intended to be the main  substance of a page.

• Plug-Ins – When a piece of code is needed throughout the site, it is best implemented as a plug-in (formerly called a Mambot). Plug-ins are commonly used to format the output of a component or module when a page is built. Some examples of plug-ins include keyword highlighting, article comment boxes, and JavaScript-based HTML editors.

• Components – Frequently have sophisticated back-end controls. The back-end is commonly used to create and update records in database tables.  A simple example would be a small guest book or a simple banner manager where the user has controls from which they can use the functionality of the component .

• Languages – Joomla! has multilingual support, which enables us to present Joomla! in many different languages. Language extensions include files that define translated strings for different parts of Joomla!.

• Templates – We use templates to modify the general appearance of Joomla!. There are two types of template extension: site templates and admin templates.

• Tools – Although referred to as extensions, tools are very different to components, modules, and plugins. The term ‘tools’ is used to describe any other type extension that can be used in conjunction with Joomla!.

Joomla Framework

The top – Extensions layer, consists of Extensions to the Joomla Framework and its applications:
Modules , Components , Templates.

The middle – Application layer, consists of applications that extend the Framework JApplication class. Currently there are four applications included in the Joomla distribution:

1. JInstallation is responsible for installing Joomla on a web server and is deleted after the  installation procedure has been completed.
2. JAdministrator is responsible for the back-end Administrator.
3. JSite is responsible for the front-end of the website.
4. XML-RPC supports remote administration of the Joomla website.

The bottom – Framework layer, consists of:

• The Joomla Framework itself.
• Libraries that are required by the Framework or are installed for use by third-party developers.
• Plugins extend the functionality available in the Framework.

References

• www.joomla.org .
• Book (Learning Joomla! 1.5 Extension Development).
• Book (Mastering Joomla 1.5 Extension and Framework Development).