This is a Blender 2.5 mushroom generator script developed by Josh Wedlake for the Tube Project. The Mushroomer Script will distribute original mushroom object over other object's surface and the result can look like this video made by Josh and Henri Hebeisen.
From the full post of while the cat is away… Josh writes:
So Bassam’s been away in Bulgaria for a couple of weeks and Henri and I mostly had the studio to ourselves. I’ve been working on a mushroom generator for a couple of timelapses – not that tube will be filled with glowing mushrooms, more that we wanted something half way between the ivy generator and a fully fledged particle system. Henri modeled some funky mushrooms and together we spun together a quick demo video just to show off some of the effects that are possible, and to exercise our fetish for indirect lighting and luminous pink.