APMO Asian-Pacific Mathematical Olympiad. Started in 1989, the APMO is a regional competition for countries in the Asian Pacific region, as well as the United States and some other countries. The test consists of a single four-hour day with five problems.

BAMO Bay Area Mathematical Olympiad. The contest is taken by several hundred students in the Bay Area annually. The format is identical to that of the APMO.

Canada Canadian Mathematical Olympiad, abbreviated CMO.

CGMO The China GirlsMathematical Olympiad. The contest began in 2002, and consists of two days, each with four problems to be solved in four hours.

EGMO The European Girls' Mathematical Olympiad, a new contest inspired by the CGMO. The first EGMO was held in Cambridge in April 2012. Currently, the contest format matches the IMO. Countries send teams of up to four female students to compete at each event.

ELMO The ELMO is a contest held at MOP every year, produced by returning MOPpers and taken by first-time MOPpers. In particular, all problems are created, compiled, and selected by students. The meaning of the acronym changes each year, originally standing for “Experimental LincolnMathOlympiad” but soon taking such names as “Exceeding Luck-BasedMath Olympiad”, “Ex-experimental Math Olympiad”, “e log Math Olympiad”, “End Letter Missing”, “Entirely Legitimate (Junior) Math Olympiad”, “Earn Lots of MOney”, “Easy Little Math Olympiad”, “Every Little Mistake⇒0”, “Everybody Lives atMost Once”, and “English Language Master's Open”.

ELMO Shortlist Like the IMO Shortlist, the ELMO Shortlist consists of problems proposed for the ELMO.

IMO The International Mathematical Olympiad, the supreme high school mathematics contest. Started in 1959, it is the oldest of the international science olympiads. The IMO draws in over 100 countries every July, and each country sends at most six students. On each of two days of the contest, contestants face three problem over 4.5 hours—problems are scored out of 7 points, so the maximum score is 42.

IMO Shortlist The IMO Shortlist, consisting of problems proposed for the IMO. About 30 problems are selected from all proposals (usually more than 100) to form the IMO shortlist. Team leaders from each country then vote a few days in advance on which problems from the shortlist will be selected to appear on the IMO.