MODx is an open source PHP Application Framework that helps you take control of your online content. It empowers developers and advanced users to give as much control as desired to whomever they desire for day-to-day website content maintenance chores. MODx is a free, fast and flexible web application framework to build sites exactly how you want with Zero restrictions.
Super-simple templates in regular HTML/CSS/JS (any lib you want). MODx is first free PHP CMS to offer an API that fully supports to Web 2.0 Ajax technology.