From Jeremie Allard (http://hufo.planet-d.net/codefr_us.php):
"This little smoke effect is coded with a little particle system done for 'The OpenGL Challenge'."
Ported to Linux by Tugrul Galatali.
OPTIONS
--root
Draw on the root window.
--maxfps number
Set maximum frame rate.
--vsync number
Limit redraws to specified number of vertical refreshes. 0 - 100. Default: 1
--dpms number
Stop rendering new frames if the display is not on. 0 - 1. Default: 1
--foreground number
Set primary (dense smoke) color using hex color codes. Default: ffffff
--background number
Set secondary (light smoke) color using hex color codes. Default: ffffff
hufo_smoke is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 as
published by the Free Software Foundation.
hufo_smoke is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.