You might enjoy the "How Google Earth Really Works" article I linked from the article. It goes into how the multi-resolution texturing works and why it's unique.

I see the lineage from SGI's Clip-Map to Keyhole's Universal Texture to Carmack's "Mega Texture" to today's Unreal's Nanite for geometry.

(not claiming anyone infringed anyone's IP, just the natural evolution of a clever idea)