Ice Age is a 2002 American computer-animated film created by Blue Sky Studios and released by 20th Century Fox. It was directed by Carlos Saldanha and Chris Wedge from a story by Michael J. Wilson. The story follows three Paleolithical mammals attempting to return a lost human baby to its parents. The film stars Ray Romano, John Leguizamo, Denis Leary, and Goran Visnjic.
The film was originally to be directed by Don Bluth and Gary Goldman, and produced in 2D by Fox Animation Studios, but the rise of CGI animation and the failure of Titan A.E. destroyed Fox's traditional animation division; hence, Bluth and Goldman transferred their duties for Chris Wedge and Carlos Saldanha from Fox's CGI division Blue Sky. The film was met with mostly positive reviews and was a box office success, starting a series with three sequels, Ice Age: The Meltdown, Ice Age: Dawn of the Dinosaurs and Ice Age: Continental Drift.
Source: Wikipedia, "Ice Age (film)", available under the CC-BY-SA License.