The X-Firewire card is Core Audio compliant, which means that it does not require a driver under Mac OSX. Simply plug in the unit and launch the application "Audio MIDI setup" which is located in the "Utilities" folder in the "Applications" folder. This will verify the presence of the unit on the firewire bus. Once the unit is installed click on "Audio Devices" and the Apogee unit should appear in the pull down menus.