Beautiful Free Animated Desktop Wallpaper: “Abstract Matrix Code”. Matrix digital rain, Matrix code or sometimes green rain, is the computer code featured in the Matrix series. The falling green code is a way of representing the activity of the virtual reality environment of the Matrix on screen. All three Matrix movies, as well as the spin-off The Animatrix episodes, open with the code. It is a characteristic mark of the franchise, similar to the opening crawl in Star Wars.