While not every GIS solution is open source, many of the early pioneers in the technology were proponents of free software. The original GIS solution MOSS (Map Overlay and Statistical System) was developed by the U.S. Department of Interior in 1978. Nearly all systems built since then, from GPS to location services, have built on the original open source solutions. Without these open source fundamentals, a large number of logistics control systems and location-based services would either not exist or still be in their infancy.