This is a direct port of my old Firedemo effect. Made to celebrate the 20th anniversary :)
See it in action at http://www.iguanademos.com/Jare/files/Fire/
Works great in IE9+, Firefox 20+ (Win and Android) and iOS Safari. Chrome on both Win and Android is rather slow, not sure why. Android Dolphin only updates a subrect of the canvas.
(C) 2013 by Javier Arevalo
This code is released under the MIT license.