Galileo is a computer reservations system (CRS) owned by Travelport. As of 2002, it had a 26.4% share of worldwide CRS airline bookings. In addition to airline reservations, the Galileo CRS is also used to book train travel, cruises, car rental, and hotel rooms.
Amadeus is a computer reservations system (or global distribution system, since it sells tickets for multiple airlines) owned by the Amadeus IT Group with headquarters in Madrid, Spain. The central database is located at Erding, Germany. The development center is located at Sophia Antipolis, France. In addition to airlines, the CRS is also used to book train travel, cruises, car rental, ferry reservations, and hotel rooms.
Sabre Global Distribution System (GDS), owned by Sabre Holdings, is used by more than 350,000 travel agents around the world with more than 400 airlines, 100,000 hotels, 25 car rental brands,50 rail providers and 14 cruise lines. The Sabre GDS enables companies such as American Airlines, American Express, BCD Travel & etc