GPSyTM connects your Mac to a broad range of Global Positioning System (GPS) receivers, Loran-C, DECCA, and OMEGA navigational units and displays your current coordinates, altitude, bearing, heading, speed over ground, velocity made good, distance to go, current waypoint, GPS satellite data, and more.

GPSyTM can upload and download GPS system data (waypoints; routes; track; almanac) from a variety of GPS manufacturers including Ashtec, Garmin, Eagle, Lowrance, Magellan, Rockwell and Trimble. GPSy is also the only Macintosh program to support the new Internet DGPS-IP services, giving you meter accuracy in real-time through from free, online DGPS-IP servers.

Limitations: The software has a locking feature built-in so that unregistered versions will only run for approximately fifteen minutes before refusing to listen to GPS input.

Requirements:
OS X 10.4-10.5
Intel

Also available is:
Universal Binary version 3.40.4 for OS X 10.3.9 or later