I just finished a first revision of an addon that supports the 3DConnexion-SpaceNavigator on OSX.
It allows you to query for the most recent update, or get notified by events as they happen.
If you’re using event notification, you can plug in an arbitrary number of devices and check for the deviceId.
There are also methods for checking the status of the buttons (there are two on the regular model) and for turning the LED on and off.
It’s a lot of fun to play with when you turn the auto background off: