The Middle Mouse Button doesn't generate mouse events on the Mac,
although the Middle Mouse Button works great on Windows.
Try the following internal sample app:
apps/internal/PlanetarySystem
The following mouse events should work:
Alt + Left Mouse Button (LMB) = Orbit the view
Alt + Middle Mouse Button (MMB) = Track/Pan the view
Alt + Right Mouse Button (RMB) = Zoom the view
All of these work great on Windows.
2 out of 3 work great on the Mac: Alt + LMB, Alt + RMB
However, Alt + MMB (Middle Mouse Button) doesn't work on the Mac.