The International Mathematical Union offers videos that were recorded at the International Congresses of Mathematicians since 1998. The IMU is grateful to the organizing committees of these ICMs for donating the videos to the IMU and allowing the IMU to place them online. The IMU maintains the copyright of the videos but grants others permission to download and show the videos as long as the IMU is appropriately credited.
At ICM 1998 in Berlin the first attempt at an International Congress of Mathematicians was made to record the opening ceremony, plenary lectures, and other major events on video. The videos were originally archived in a format that has since become obsolete, but they could be recovered and converted to current video standards. While some older videos are not particularly great quality visually, many undoubtedly remain of long term historic interest (e. g., see Andrew Wiles' lecture on Fermat's problem).
Video recording became more professional at ICM 2002 in Beijing, where most of the major events and lectures were also recorded. Further improvements in recording were visible at ICM 2006 in Madrid. The organizers of ICM 2010 in Hyderabad and ICM 2014 in Seoul continued this "video tradition" and recorded the opening ceremony and the plenary lectures. More extensive recording - including sectional lectures - has since become the standard at subsequent ICMs, with the videos hosted on dedicated YouTube channels managed by the IMU.