Joomla Directory, Joomla Links, Joomla Extensions, Joomla Templates- Joomla Official

Joomla API Reference
Application Programming Interface for Joomla.
http://api.joomla.org - Details

Joomla Extension Directory
The official Joomla extension directory.
http://extensions.joomla.org - Details

Joomla Code
JoomlaCode.org is a resource for developers to build and manage Open Source software projects centred around Joomla! With JoomlaCode.org we aim to help build Open Source tools and extensions for the Joomla! user community by providing resources to help developers work together in an Open Source spirit.
http://forge.joomla.org/ - Details

Joomla Community Forum
The official Joomla community forum.
http://forum.joomla.org - Details

Joomla Help Site
The official Joomla help site.
http://help.joomla.org - Details

Joomla Developer Network
The official Joomla Developer Network. Development information and resources for Joomla.
http://dev.joomla.org - Details

Joomla Demo Site
The official Joomla demo website.
http://demo.joomla.org - Details

Joomla Shop
The official Joomla shop for all your Joomla merchandise needs.
http://shop.joomla.org - Details

Joomla! Wikipedia Article
Encyclopedia article about the system, including history and features.
http://en.wikipedia.org/wiki/Joomla%21 - Details

Joomla
Joomla! is one of the most powerful Open Source Content Management Systems on the planet. It is used all over the world for everything from simple websites to complex corporate applications. Joomla! is easy to install, simple to manage, and reliable.
http://www.joomla.org - Details