Mac users interested in Basecamp for osx 10.6.8 generally download:
Manage Garmin data from a Mac. View and organize your maps, waypoints, routes, and tracks, send the results directly to a connected device, and check the integration for immediate use. Create routes for different types of activities, such as driving, motorcycling, walking, hiking, tracking, etc.
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.