r.ros(1grass) on Linux
The text 92f4b10fb25d, as Debian 9 (Stretch) shipped it.
Generates rate of spread raster maps. Generates three, or four raster map layers showing the base (perpendicular) rate of spread (ROS), the maximum (forward) ROS, the direction of the maximum ROS, and optionally the maximum potential spotting distance for fire spread simulation.