In the scene where Leito (David Belle) is being chased near the beginning of the film, he is using Parkour, which was invented by Belle himself and influenced by his father Raymond Belle. There weren't any special effects (wirework, computer graphics...) used in 90% of the Parkour scenes.
The whole movie took 10 months for production (idea, script, casting, filming, etc), January 2004 - October 2004.
Despite common misunderstandings, the film is set in 2013 not 2010.
The opening script on screen say that the sectioning off of District 13 was actioned in 2010 and as the camera surveys the wall you see markings that say "completed Oct 2010" in French.
Then it says "Three years later" as the main film starts, making it 2013 and the sequel is 2016.
David Belle nailed the stunt where he jumps up and smashes through the tiny window above a door in just two takes.
David Belle would play the role again alongside Paul Walker in Brick Mansions, which is a remake of this film.