On Track is an audible mobility program designed for use by individuals who are blind or have low vision. This software program converts heading / course information from any standard global positioning system (GPS) device into audible tones that tell the user which direction to take and how much to turn to follow the desired course. The audible tones are delivered via a personal computer's speakers or headphones. This software may be used by hikers, sailors, and others who need to follow a heading or aim for a specific location. The user presses start and enters the desired heading or target point. Headings and target points can be changed at any time and the program will provide audible tones to direct the user which way to turn and by how much. COMPATIBILITY: For use with IBM and compatible computers or personal data assistants. SYSTEM REQUIREMENTS: Windows 95/98/2000/XP/NT or PDA-Palm and Pocket PC, and a GPS with a serial port.