scene resource sharing Blender allows editing of more than 1 scene at a time. Can resources be shared between edited scenes, such as meshes and textures? What resources does a scene own and what resources does it only reference? I am writing an exporter for more than one scene at a time, but no resources appear to belong to a scene, so I am confused.

Say, Object1 is in scene1, can another scene also own Object1? I'd be surprised, since the object has a scene transformation matrix associated.
You can link one object to multiple scenes with Ctrl + L, that way the same object will be used and any edits will apply to others scenes. If you want to use a different object but the same mesh, that is possible with instancing using Alt + D.