Plone!

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.

Trusted by 8,000 businesses, Confluence is the leading collaboration software and enterprise wiki for intranets and knowledge management. Free 30-day trial.

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.

CMS Made Simple - the open source content management system for the rest of us. CMS Made Simple helps experienced web developers and designers to create sites of power and beauty in a fraction of the normal time, avoiding hours of coding and allowing your clients to update their own sites with a minimum of fuss. From a simple brochure site to a complex portal, CMS Made Simple puts the power of a modular and extendable content management system at your fingertips. And best of all, its free!

Craft gives you the tools to sculpt a content management experienceprecisely tailored to your site’s needs.

A powerful newcomer in the CMS field with lots of great modules like blog, e-commerce, easy to develop and maintain, good looking and user-friendly.

blogstrap.py is a simple, no frills blog content management system powered by Twitter's Bootstrap and web.py. It features most things you would come to expect from a simple blogging platform. You can browse posts by category or subcategory, see recent posts, and mark favorites. You can perform basic searches. It includes an About page. A basic tag system is implemented (popular tags are counted and shown). A simple comment system is available. A robust administrative interface is included where you can create and edit posts. You can upload images and include them on a Credits page, where you can properly attribute the original author. Comments can be set to on, off, or manual approval (moderated). Security has been a top priority since the beginning. Blogstrap.py has low resource usage and runs quickly on top of Lighttpd. »