The series was originally broadcast in French in Canada, and the episodes were later translated into English for the US. The original books were also in French. "Caillou" was designed primarily for toddlers. It was created by child developmental psychologists. In 1997, 65 five-minute episodes of "Caillou" were aired in Canada and in selected markets worldwide, including the US. In 2000 there were 40 thirty-minute episodes of the show, containing a mixture of the five-minute episodes plus new stories, songs, real kids segment and puppets. This was followed by another 16 thirty-minute episodes containing all-new stories in 2003. The film "Caillou's Holiday Movie" was released on October 7, 2003. On April 3, 2006, a new set of 20 episodes finally premiered after a three-year hiatus. Caillou started attending preschool and there were new themes and a new opening. The show was renewed for a 2nd and 3rd season in 2003.