Motivations for using the OpenSceneGraph

Performance - culling and sorting

Productivity - encapsulates useful functionality

Portability - develop and deliver on the platforms of your choice

Interoperability - rendering is only part of the story... you have to integrate

Extensibility - if it ain't there add it!

Scalability - palmtop to infinite reality monster?!

Source - the naked truth.

Community - hey we're all friends round here :)