The World Federation of National Mathematics Competitions (WFNMC) was founded in 1984 as a professional organization that provides the possibility of international collaboration among mathematicians and mathematics educators working in the area of mathematics contests. Over the last decades the field, which has come to be called “competition mathematics for school students”, has developed new methods for two important activities in mathematics education, namely, problem posing and problem solving. Because of this development, competition mathematics has shaped itself into a separate branch of mathematics education with its particular features, trends and needs. It not only contains the seeds of many fields of contemporary mathematics, but has also stimulated rich contributions to important research areas of mathematics education, in the intersection of the interests of both professional communities. Mathematics competitions serve also to identify mathematical talent worldwide and to promote the attraction of young people of higher ability to professional careers in mathematics. In many cases, problems posed in mathematical contests inspire mathematical research and new methods of teaching mathematician. In this paper I briefly describe the history of WFNMC. I focus on the main activities of the Federation, including conferences, awards, publications, and research areas of the members. As the only international professional organization in this field, the WFNMC supports activities that have their own particular significance, which are discussed in the paper.