The IMB Jena Image Library of Biological Macro-molecules (http://www. imb-jena.de/IMAGE.html ) is aimed at a better dissemination of information on three-dimensional biopolymer structures with an emphasis on visualization and analysis. It provides access to all structure entries deposited at the Protein Data Bank (PDB) and Nucleic Acid Database (NDB). By combining automatic and manual processing it is possible to keep pace with the rapidly growing number of known biopolymer structures and to provide, for selected entries, information not available from automatic procedures. Each entry page contains basic information on the structure, various visualization and analysis tools as well as links to other databases. The visualization techniques adopted include static mono/stereo raster or vector graphics representations, virtual reality modeling (VRML), RasMol/Chime scripts and Java applets. A helix and bending analysis tool provides consistent information on about 750 DNA and RNA duplex structures. Access to metal-containing PDB entries is possible via the Periodic Table of Elements. Finally, general information on amino acids, cis -peptide bonds, structural elements in proteins, base pairs, nucleic acid model conformations and experimental methods for biopolymer structure determination is provided.