http://www.cica.indiana.edu/graphics/3D.objects.html
The Center for Innovative Computer Applications at Indiana University presents this extensive document on various 3D object file formats and how to view them from a Web browser. Some of the formats have detailed format specifications available by clicking on the format name. The contents of this home page cover the 3D Object file formats, Virtual Reality Modeling Language Object file formats, Viewing 3D objects from within a Web browser, A sample 3D object in OOGL format, and a discussion of some problems you may encounter.