Oktoberfest is a German festival- an ode to beer, of sorts- taking place in Munich (in Bavaria). The 2013 Oktoberfest lasts from September 21st until October 6th. With over 6 million people in attendance each year, it is the largest fair in the world.
The traditions started with the marriage of Crown Prince Ludwig and Princess Therese of Saxony-Hildburghausen on October 12, 1810. There were celebrations by the fields, later named Theresienwiese, or "Theresa's Fields." One of the activities was horse racing, and the decision to repeat the horse races led to the tradition of Oktoberfest. Horse racing traditions ended in 1960, save for the 200th anniversary in 2010.
From 1939 to 1945, there was no Oktoberfest. From 1946 to 1948, there was only an Autumn Festival.
The dates of Oktoberfest were rearranged in 1994 so that October 3rd, the date of the reunification of Germany, could be included in the 16-day festival each year. The festival features many German foods such as Schwinshaxe and Knödel.
The festival, since 1950, has opened the following way: the mayor of Munich taps the first keg of Oktoberfest beer at noon, accompanied by a twelve gun salute, with a cry of "Ozapft is!" ("It's tapped!") The first beer is then given to the Minister-President of Bavaria.
Since 2005, beer tents have been restricted to quiet music until 6:00 pm, when loud pop music is then played. Authorities have also gone back and forth throughout the years on the sale and use of tobacco products within enclosed spaces during Oktoberfest.
Oktoberfest popularized the stereotypical image of German clothing such as lederhosen from males and dirndl from females.
Sources: Wikipedia, Muenchen.de, Oktoberfest.de