Joomla 1.6!

Joomla is a free, open-source content management system (CMS) and application framework that powers 2.7% of the entire web. With a vibrant volunteer community, user-friendly features and plenty of power, Joomla is perfect for your site!

Joomla 1.6 Beginner Guide
How to install template for Joomla 1.6
Joomla latest version