A program is described that allows the user to analyze and display atomic structures on any Macintosh personal computer. The program reads ASCII format structure files including PDB, plot files from the graphics programs O and FRODO, and Cartesian coordinates from ChemDraw 3D. The program has a graphical interface that features floating button palettes for objects and tools. The structures may be displayed using stick, ball-and-stick, space-filling, and ribbon models. Each type of drawing can be colored according to a variety of schemes to accentuate various structural aspects. The figures can be rotated, displayed in stereo, and exported using the Clipboard, PICT files, or Quick-Time movies. The structure can be further analyzed by displaying hydrogen bonds, making Ramachandran plots, labeling atoms, measuring distances, and finding neighboring atoms. By using the Macintosh computer and emphasizing a graphical interface, this program helps to bring structural analysis to students and researchers that may not have access to, or experience with, large graphics workstations. In addition, the object-oriented output PICT images are ideal for creating publication-ready diagrams that can be easily modified or inserted into other documents (e.g., see Refs. 1-3).