r.spread(1grass) on Linux
The text 217c651b2a95, as Debian 8 (Jessie) shipped it.
Simulates elliptically anisotropic spread on a graphics window and generates a raster map of the cumulative time of spread, given raster maps containing the rates of spread (ROS), the ROS directions and the spread origins. It optionally produces raster maps to contain backlink UTM coordinates for tracing spread paths.