The ELMO is an annual math olympiad that happens at MOP. Its initials have stood for many things over time, originating from a backronym originally called the "Experimental Lincoln Math Olympiad". The black MOPpers and returning MOPpers write and organize the test, and lead the teams of competitors, which consist of rookie MOPpers. The team leaders present their teams' solutions to the graders, imitating the grading process of the IMO. The ELMO began in 1999.