It was originally but LabVIEW for MAC should be able to open it. Start LabVIEW, chose open, and select the .llb and you should be able to see the VIs inside. I don't think there's anything you can do from the MAC OS to view the contents of a LabVIEW library. I'm reattaching the file in case it got mangled somehow. I wish I had a MAC to verify the contents but I don't.