Mac users interested in Garmin express for osx 10.6 generally download:
Work with Garmin hardware by connecting the compatible devices to your Mac and checking for updates of firmware or importing and upgrading the database of GPS maps. Reading detailed device information is possible along with online sharing of the map data.
The no-hassle way for devices with nüMaps Lifetime™ subscriptions to get map updates. Garmin Lifetime Updater continually checks for available map updates and automatically downloads them to your computer. It then alerts you right on your desktop when files are ready to install.
Upload, copy and update map files on Garmin USB GPS devices or SD cards. The utility automatically assigns the selected files and provides options to unlock codes to the right path in order to make the maps accessible for MapInstall and Training Center. Browsing maps, previewing them and zooming in on specific areas is possible.