Is a molecular visualization software adapted from the program RasMol. I had been looking for a replacement for the formerly free WebLab Viewer program, and this is an outstanding candidate. RasTop wraps a user-friendly graphical interface around the "RasMol molecular engine". The software allows several molecules to be opened in the same window and several windows to be opened at the same time. Through an extended menu and a command panel, users can manipulate numerous molecules rapidly and learn about them. In addition, users can export to POVRay to create artistic renderings of molecules