• concrete5 - open source, free CMS
• Drupal - an open source content management platform
• ExpressionEngine - by Ellis Lab
• Joomla! - mobile-ready and user-friendly way to build a website. Joomla! is free and open source.
• TextPattern - a flexible, elegant and and easy-to-use CMS
• Contao - web-based Open Source Content Management System, formerly known as TYPOlight
• SilverStripe - create innovative websites and applications
• Umbraco - open source ASP.NET CMS
• WordPress

• The David Byrne Approach to Content & Community Management and the use of GIFs
• Top 10 Content Management Systems - strengths and weaknesses

Also See