iMol

iMol displays the structure of chemical substances at their molecular level. The application is designed for both learning and teaching purposes.

With this tool you can change multiple rendering settings including style, view, selection, label and animation parameters. iMol features support for different molecular files like PDF, MOL, ALC, HIN, BIO or XYZ.

Users may select one of three manipulation modes: everything, molecule, fragment. With the help of the Drawer side panel, you can modify how the atoms and their connections are displayed.

When dealing with large molecular structures, iMol provides four methods for selecting atoms: buttons, mouse, query and a hierarchical view. Once a selection has been highlighted, you can delete atoms from the molecule.

While the application allows users to save the molecule under a graphic format (TGA), no video output is available at this time.

I found iMol very intuitive to use; the fact that it comes with several examples, made it easy to check the program's features when dealing with simple (methane) as well as complex (DNA) molecular substances.