As a technology, global positioning systems has been around for the greater part of the last 20 years. Though this technology started off as a military project, there was an initial concession to civilian use by hobbling the data. Early civilian use of GPS was accurate to a hundred feet, while the military GPS devices were accurate to around 10 feet. Only during the past ten years was this limitation lifted for civilian use, prompting practical applications for a wide-range of devices.
Until recently, the software for GPS maps was a simple vector-directional feed. That meant that either you were reading numerical data, and reading your position from a map, or the GPS device homed in to a transponder and the numbers included range and direction. This was okay for military or rescue purposes and for trekking, or camping use.
Nowadays, GPS maps software are already included in GPS navigation devices, allowing ordinary drivers or field personnel so see their location super-imposed on a map.