MushRaider is a Modern Raid Planner mainly designed for MMORPG. It's written in PHP 5.x and need a MySQL database. It supports multi gaming and can be fully customize.
For more information please visit the official page
Sure ! MushRaider is based on the framework CakePHP so you can easily create plugins to get more functionnalities (like a phpBB/wordpress/nuke/whatever's bridge, just a hint).