CMS
Content Management Systems gives you access to the back end allowing you to add your own content.
WordPress
“WordPress is web software you can use to create a beautiful website or blog. We like to say that WordPress is both free and priceless at the same time.”
Drupal
“Drupal is an open-source platform and content management system for building dynamic web sites offering a broad range of features”
MediaWiki
“MediaWiki is a free software wiki package written in PHP, originally for use on Wikipedia. It is now used by several other projects of the non-profit Wikimedia Foundation and by many other wikis.”
Joomla
“Joomla is an award-winning content management system (CMS), which enables you to build Web sites and powerful online applications. “