Nimo
NIMO is the National Internet Mathematics Olympiad. (Idea developed by isabella2296 and site hosted by Dojo) Debuting in 2009, NIMO is supported by 5 well known AoPS users - specifically:
AIME15, Dojo, dragon96, isabella2296, and Mewto55555
The annual tests for 9th graders or below are also helped written by the AoPS users:
DeltaX and pythag011
There is also a user, Jongao, with a secret identity. The AoPS subforum is located here. Read more about the competition and be a cyber pioneer today, at: