The ELMO is an annual math olympiad that happens at MOP. Its initials have stood for many things over time, such as Experimental Lincoln Math Olympiad (the original acronym), Ex-experimental Math Olympiad, Easy Little Math Olympiad, Extremely Last-Minute Olympiad, e^log Math Olympiad, End Letter Missing, Exceedingly Loquacious Math Olympiad, Entirely Legitimate Junior Math Olympiad, and (most recently) English Language Master's Open. The black MOPpers and returning blue MOPpers write and organize the test, and lead the teams of competitors, which consist of red MOPpers and rookie blue MOPpers. The team leaders present their teams' solutions to the graders, imitating the grading process of the IMO. The ELMO began in 1999.