SPIP!

Friendica is a distributed social network application which runs on commodity hosting platforms - PHP/MySQL/Apache. (If you can install Drupal or Wordpress you can probably install Friendica)

Social networking in a box. Build a social network for your company, school, sports team or niche community all based on the power and flexibility of WordPress. Install BuddyPress directly through your WordPress dashboard plugins page, or download it manually from the WordPress.org plugins repository.

Tiki Wiki CMS Groupware is a full-featured, web-based, multilingual (40+ languages), tightly integrated, all-in-one Wiki+CMS+Groupware, Free Source Software (GNU/LGPL), using PHP + Smarty, MySQL, Zend Framework, jQuery and Bootstrap. Tiki can be used to create all kinds of Web applications, sites, portals, knowledge base, intranets, and extranets. It is actively developed by a very large international community.

django CMS is an Enterprise Content Management built with Django and one of the most active open-source projects in the Django ecosystem. Since 2007 it powers tens of thousands of sites large and small across the world, and benefits from a friendly and welcoming developer community.

Plone is an open source content management system based on the Zope application server, written in python. Its known to be powerful, reliable, secure and easy to use. Plone excels when compared to other content-management systems in standards conformance, access control, internationalization, aggregation, user-generated content, micro-applications, active user groups and value. Plone website editing gives you more of a "wysiwyg" feel than most content management systems.

ImpressPages is a PHP framework with admin panel. A new MVC engine is under the hood so you can customize ImpressPages in no time. Write your own plugins and themes to suit your and customers’ needs best. Both website layout and administration interface are user friendly and simply gorgeous.

modx is a free, fast & flexible, ajax and seo content management systemMODx helps you take control of your online content. An Open Source Content Management Framework, it frees you to build sites exactly how you want and make them 100% yours. Zero restrictions and fast to build. Super-simple templates in HTML/CSS/JS (any lib you want). Registered user systems and a killer community. Welcome to web-building nirvana.

Many content management systems are focused on developer or site owner needs, but concrete5 is a CMS that truly delivers the best to both worlds. An in-context editing toolbar makes it easy to make changes as you navigate the live website. A truly MVC architecture and API make it easy for developers to truly use the CMS as building blocks.

Redaxscript is a modern, ultra lightweight and rocket fast Content Management System for SQLite, MySQL and PostgreSQL.