Cn3D (See in 3D) is a separate application which allows you to view 3-dimensional structures from the Structure database. It is available for Windows and Macintosh and can also be compiled on Unix.
iCn3D (I see in 3D) is a WebGL-based view for interactive viewing of 3-dimensional macromolecular structures and chemicals on the web.
CBLAST compares a query protein sequence against all protein sequences from experimentally resolved 3D structures.