European airlines also began to invest in the field in the 1980s initially by deploying their own reservation systems in their homeland, propelled by growth in demand for travel as well as technological advances which allowed GDSes to offer ever-increasing services and searching power. In 1987, a consortium led by Air France and West Germany's Lufthansa developed Amadeus, modeled on SystemOne. Amadeus Global Travel Distribution was launched in 1992. In 1990, Delta, Northwest Airlines, and Trans World Airlines formed Worldspan, and in 1993, another consortium (including British Airways, KLM, and United Airlines, among others) formed the competing company Galileo GDS based on Apollo. Numerous smaller companies such as KIU have also formed, aimed at niche markets not catered for by the four largest networks, including the low-cost carrier segment, and small and medium size domestic and regional airlines.