1. Frog CMS
Frog CMS simplifies content management by offering an elegant user interface, flexible templating per page, simple user management and permissions, as well as the tools necessary for file management.
Frog requires PHP5, a MySQL database or SQLite 3 with PDO, and a web server (Apache with mod_rewrite is highly recommended).
SilverStripe open source content management system and framework intuitive and user-friendly, fast, flexible, and free, to build powerful websites quickly.
Liferay is a leading provider of open source enterprise portal and social collaboration software. Liferay Portal is all about choice. It gives you over 60 portlets and the most innovative technologies to let you do everything from web publishing, to building an intranet, to simply getting the right documents and applications to the right people.
MiaCMS is a powerful, flexible, and easy to use open source content management system. It can be used to build websites of all shapes, sizes, and scenarios. MiaCMS features simple installation, graphical (WYSIWYG) HTML editors, RSS content syndication, a powerful 3rd party extension system, flexible theming capabilities, site search, RESTful content access, user management, multilingual capabilities, plus much more.
MoinMoin is an advanced, easy to use and extensible WikiEngine with a large community of users. Said in a few words, it is about collaboration on easily editable web pages.
ImpressCMS is a community developed Content Management System for easily building and maintaining a dynamic web site. Keep your web site up to date with this easy to use, secure and flexible system. It is the ideal tool for a wide range of users: from business to community users, from large enterprises to people who want a simple, easy to use blogging tool.
MODx is 100% buzzword compliant, and makes child's play of building content managed sites with validating, accessible CSS layouts – hence Ajax CMS. It empowers its users to build engaging "Web 2.0" sites today, with its pre-integrated MooTools, Scriptaculous and Prototype libraries.
Textpattern is a flexible, elegant and easy-to-use content management system PHP-based. It is both free and open source.
Radiant is a no-fluff, open source content management system designed for small teams. Main features: elegant user interface, flexible templating with layouts, snippets, page parts, and a custom tagging language, first-class extension/plugin system, simple user management and permissions. Platform: Ruby.
10. CMS Made Simple
If you are an experienced web developer, and know how to do the things you need to do, to get a site up with CMS Made Simple is just that, simple. For those with more advanced ambitions there are plenty of addons to download. And there is an excellent community always at your service.