OGRE 3D Programming

The OGRE 3D graphics engine has become real popular in open source game development, and meanwhile is an alternative for some commercial developers, who already using it. A notable thing is the good documentation about the engine, a friendly community, and even now a book - Pro OGRE 3D Programming (2006). In my opinion this makes the position of OGRE very clear as a constant among (FOSS) 3D graphics rendering engines.