What does the Commission on Presidential Debates do?

The Commission on Presidential Debates (CPD) began in 1982 by both the Democratic and Republican parties to establish a way to run presidential debates between the candidates that are running for President of the United States. The CPD sponsors and produces debates for the United States presidential and vice presidential candidates and undertakes research and educational activities relating to the debates. The organization, which is a nonprofit corporation controlled by the Democratic and Republican parties, has run each of the presidential debates held since 1988.

Source: http://www.debates.org/