Hi, this is a relatively good webcam but on a Mac, some of the features will not function without software. First of all, the software for this cam is written for PC only, but the camera will operate pretty well without it.
You will need to upgrade to OS X 10.4.9 or higher, or download and install "ichatUSBCam" at this link...
http://www.macupdate.com/info.php/id/12294
10.4.9 and 10.4.10 will recognize the cam natively.
All the cool features like snapshots, auto-focus, face tracking, etc... will not be available without the PC only software. I contacted Logitech about the auto-focus not working and they told me that the Pro 9000 has internal hardware that requires software control.
I have found the focus to not be a problem as almost everything is in focus anyway.
This cam is very sharp, very high resolution and auto-exposure and color balance seem to work great.
Hope this helps,
Pete