This book is a concise introduction to OpenSceneGraph (OSG)—the open source, cross-platform scene graph application programmer interface (API). OSG plays a key role in the 3D application software stack. It’s the middleware above the lower-level OpenGL hardware abstraction layer (HAL), providing extensive higher-level rendering, I/O, and spatial organization functionality to the 3D application.

The Quick Start Guide and OpenSceneGraph Reference Manual - can now be purchased from their website this site is no longer operating. The Quick Start Guide is also available as free pdf download, just follow the links on the osgbooks website mirrors can be found using your favourite search engine. Purchasing books helps fund ongoing documentation efforts so its a great way to help put something back into the project.