The Davis Cup is the premier international team event in men's tennis. The largest annual international team competition in sport, the Davis Cup is run by the International Tennis Federation (ITF) and is contested between teams of players from competing countries in a knock-out format. The competition began in 1900 as a challenge between the United States and Great Britain. In 2005, 134 nations entered teams into the competition. The United States is the most successful nation to date, winning 32 tournaments and finishing as runners-up 29 times. Australia is the second most successful, winning 23 times and finishing second 18 times and also participating in winning 5 times and second once with New Zealand under the alias 'Australasia'. The women's equivalent of the Davis Cup is the Fed Cup.