TangoCMS is a free and Open Source (GNU/GPL 2.1) PHP Content Management System (CMS). Its ease of use and powerful feature set allows you to quickly and easily create and manage an entire website.

We aim to develop a content management system that;
Complies to W3C HTML standards.
Is built with security in mind.
Powerful yet easy for anyone, even with basic web knowledge, to use.

TangoCMS offers many Features to help you manage your website, publish content and speed up your work flow - including a powerful media module to display videos, pictures and audio files! With an ever growing Community, you will always get the best support with any problems or questions you come across.

http://tangocms.org