Shane Acker first made 9 - A Salvação (2009) as a ten minute short film while he was still at UCLA. It was nominated for Best Animated Short at the Oscars, and although it didn't win, Acker was offered the chance to expand it into a feature film. It follows the same basic plot, but more characters have been added, they have the ability to talk now, and the reason for the world's destruction is explained in more detail.
Alan Oppenheimer plays the scientist responsible for the destruction of the world. So it seems fitting that he's the cousin of J. Robert Oppenheimer, the "Father of the Atomic Bomb."
The clock on the Notre Dame Church is stuck on the time 9:09.
A canny choice of the marketing department was to give the film a release date of September 9, 2009 (09/09/09).
The first ten minutes have almost no dialogue -- much like the dialogue-free 11-minute short film that this movie is based upon, 9 (2005).