There are several publications about the International Mathematical Union produced for, and displayed at the ICSU General Assembly in Rome, September 2011.
The publication about IMU is the article "The New IMU Needs You!" written by Herbert Clemens, Ingrid Daubechies, and Carol Wood and published in "Notices of the AMS", Volume 61, Issue 6, 2014.
John Ball, president of IMU for the period 2003-2006, provides a general survey on the work of IMU The IMU and You, published in "Notices of the AMS", Volume 52, Number 10, 2005.
Information about IMU and the state of mathematics can be found in an interview about the role of mathematics and the preparations of ICM 2006 in Spain that John Ball gave to "Boletín de la Sociedad Española de Matemática Aplicada" 33(2005)19-26.
IMU's former president David Mumford, 1995 - 1998, and Allyn Jackson, Senior Writer and Deputy Editor of the "Notices of the American Mathematical Society", described the work and structure of IMU in the column »What is IMU?«, published in the Notices of AMS, Nov./Dec. 1994:
The articles are reproduced here under permission.