Table 1. Server classes and descriptions.

Server class	Server description
Administration	List residue
	List sequence
	List coordinates
	Renumber a file
Structure validation	Check packing quality
	Check Ramachandran plot
	Check crystal packing clashes
	Check bond angles (or distances, planarities, etc.)
Protein analysis	Accessibility, secondary structure and crystal contacts
	Protein ligand contacts
2D graphics	B-factor plot
	Ramachandran plot
3D graphics	Molecule coloured by B-factor
	Transparent arrow-and-cylinder drawing
	A simple alpha carbon trace
Cysteine related	List cysteine bridges
	List torsion angles of cysteine bridges
Water related	List waters near residues
	List residues near waters
	Move waters to the correct symmetry position
	Add crystallographically related waters missing in PDB file

About 100 servers are divided into 20 classes, approximately.

The left column lists some of these classes, while the right column lists a few servers of each of those classes.