Most Popular CMS Software to Develop your Skills

WordPress - Blog Tool, Publishing Platform and CMS.

Joomla - The CMS Trusted By Millions for their Websites.

Drupal  - Open Source CMS.

ModX -  You need little or no coding knowledge to use.

TYPO3 - The Enterprise Open Source CMS.
 

Text Pattern - With a minimalist, direct admin interface and flexible design engine

RefineryCMS - Based on the Ruby on Rails framework

Weebly - Create a free website and a free blog

DotNetNuke - The world of CMS solutions is chock-a-block full of software written in PHP