YurikoCMS is a highly Object Oriented Content Management System written in PHP. It's still a fairly young project so there are no stable releases yet and the API is constantly changing. You can follow the progress on redmine or Github and any help submitting tickets or feature requests is appreciated.

Goals of YurikoCMS

Lightweight Core Module

The core of the CMS will only handle basic functionality and have nothing to do with any of the content types. The core will basically only handle the management of the plugins and other modules.

Completely Modular Content

With each site needing specific kinds of content, YurikoCMS will allow developers to create different content plugins to handle any kind of content. From simple text content or navigation menus to more complicated wikis or bulletin boards.

Fully customizable Themes and User Interfaces

The themes and user interfaces are almost completely separated from the core. Similar to how plugins are added, themes are easy to create and enable.

Cascading Filesystem for Themes

Themes can overwrite any View in the application but don't need to. With the cascading filesystem, any View not defined in a theme is automatically taken from the default theme.

Developed by Kohana

http://yurikocms.com/home
http://gitorious.org/yuriko_cms