Immortal Grand Prix (IGPX) refers to two anime series co-produced simultaneously by Cartoon Network and Production I.G. The first is a "microseries" consisting of five 5-minute episodes. The second is a loosely-related 26-episode animated series.

Koichi Mashimo co-wrote, and directed the micro-animated the series, while Bee Train Animation and Production I.G animated it, and Bandai Entertainment acted as the North American distributor. The full length Anime series was handled by director and writer Hongo Mitsuru and was animated by Production I.G with Bee Train returning for in-between animation.

The series' production was managed by Williams Street in Atlanta, Georgia. Bang Zoom! Entertainment in Burbank, California produced the English dub for the series, as well as adapted the scripts alongside Williams Street.

An IGPX video game was released on September 12, 2006 for the Sony Playstation 2.

Source: Wikipedia