Right now, the software provided by Garmin is only available for PC. Garmin has announced plans to release a version of Training Center for the Macintosh in Spring 2006.
Some users have successfully connected Forerunner 201 to Macs using a USB-to-serial adapter and then retrieved tracklog data using native Mac software such as MacGPSPro. This works well for mapping.
Newer Forerunner models also have data for heart rate, workout programs, and courses. These features are only supported by software that's specifically designed to work with Forerunner & Edge.