You can translate, rotate, or resize the molecule on the canvas with a simple mouse drag. The View Menu and Pop-up Menu both contains a Transform submenu that allows you to set the type of motion to apply to the molecule.

By Selecting Translate or Drag, dragging the mouse across the canvas will result in a same displacement of the molecule.
Selecting Zoom allows you to resize the molecule. Dragging the mouse upward will zoom out, dragging downward will zoom in.
Selecting Rotate in 2D allows you to rotate the molecule in 2D. The center of the molecule becomes the center of rotation and the molecule will rotate around this point in the direction of the mouse drag.
Selecting Rotate in 3D allows you to rotate the molecule in 3D around a point at the 3D center of the molecule.
If you select the Zoom/Rotate option and drag the mouse on the canvas, you can zoom the content of the canvas and/or rotate it in 2D.

The View Menu and the Pop-up Menu also contains the Animation menu, which allows you to start and stop an automatic 3D rotation of the molecule.