Inline nodes can load other VRML/X3D scenes into the current scene, helping authors reuse models to build larger worlds.
An Inline node creates a special group from another scene's contents.
Children nodes are read from the file selected by a URL, and every child node loaded from the group is displayed.
These X3D scenes are adapted directly from the
original VRML 2.0 Sourcebook chapter examples.
Introduction to VRML97 SIGGRAPH98 course notes.