Jmol

Jmol, an open-source Java viewer for chemical structures in 3D with features for chemicals, crystals, materials and biomolecules.

Jmol Viewer Website

 

Interactions

Basic Commands
Open Jmol Menu Right Click
Ctrl + Left Click
Left Click on Logo
Rotate Around X,Y Left Click and Drag
Move along X,Y
(= translate)
Shift + Left Double-Click and Drag
Middle Double-Click and Drag
Ctrl + Right Click and Drag
* Works both when clicking on the molecule or away from it.
Reset and Center Shift + Left Double-Click
Middle Double-Click
* Only works if double-click is done away from the molecule.
Rotate Around Z Shift + Left Click and Drag Horizontally
Middle Click and Drag Horizontally
Shift + Right Click and Drag Horizontally (possibly fails on OS X)
Zoom In / Out Shift + Left Click and Drag Vertically
Middle Click and Drag Vertically
Use Mouse Wheel