Welcome to OpenSG.
OpenSG is a scenegraph system for realtime rendering, e.g. for Virtual Reality applications. It is just a library, not a full application.
This documentation contains descriptions of the internal classes and concepts, as well as a tutorial that explains how to use the system.
The classes are easiest to find via the Class Hierarchy at the top of the page. This is a pretty long list, a more structured approach can be made via the Modules page.
The tutorial starts here: Preface. It is organzied as the first part of the Related Pages section, and there are some other pages that are more of a description than a tutorial at the end of the Related Pages section.
This documentation contains information about extending the system, i.e. what to do when adding new classes to the system to make sure they are registered in all the right places and integrate themselves seamlessly.
It also contains additional information that explains the internals and how things work inside the library itself, for those who really need to know.
While we tried to make this documentation easy to understand and without mistakes and errors, we're very interested in getting feedback on omissions, improvement ideas or simply typos. Send them to email@example.com.