3DXML

3DXML is an XML and ZIP based file format for 3D representation files. The 3DXML file is actually a ZIP archive, and the contents include either XML or binary data defining 3D meshes or surface data. It is a proprietary format, though specs were at one point available via the official website; however, that site is now down and the archived copy only points to a page saying you need to register at the now-nonexistent site to get access to the documents.

Links

 * Wikipedia article
 * Archived copy of official site
 * Open source viewer