A new version of ProteinWorkshop is coming which should solve the bugs reported from subscribers to this list - thanks for the feedback. It also adds biological unit rendering. An image from this version recently used in a calendar: http://spdc.sdsc.edu/1aq4_per_pixel_overview.tif (28 megs) Ribbons of the largest biological unit in the PDB: http://spdc.sdsc.edu/iedb/protein_workshop/1ej6_big.tif (45 megs) - 0.2 frames per second on a 3.2 ghz computer with a good (though not spectacular) video card - Requires a computer with 256 megs of system ram - For these extra-large molecules, I'll add a rendering progress bar like PyMol uses. As far as I know, this means that every molecule in the pdb (biological and asymmetric) is viewable using ProteinWorkshop.