MVP (Macromolecular Visualization and Processing) is a convenient tool for visualizing macromolecular structures and their derived information. It supports PDB format and EM density maps and has many drawing styles and color modes. It contains lots of convenient features, including computations of triangulated surfaces, depth, principal axes and estimate the secondary structures for protein structures etc. References: Dong Xu, Yang Zhang (2009) Generating Triangulated Macromolecular Surfaces by Euclidean Distance Transform. PLoS ONE 4(12): e8140. Registration not required.