I was just reading the Durian page and saw that they were in need of textures.
In my projects I came across this program: MaPZone
It creates images algorithmically, and I have seen (and made) some very beautiful textures.
Algorithmic - can create an image from scratch.
(It can also work off an image as well)
Free - (not open source though.)
Output - Alpha, Diffuse, Bumpmap, and a few others.
Looping Textures - as I remember it automatically makes looping textures.
Amazing textures - did I mention that it makes amazing textures?
Works in windows - Wine has trouble, but it does work
kind of strange - But if you know how to use Blender nodes, this will be easy.
Closed source - does that automatically kick it from the running?
I thought that the guys over at Durian should at least take a look, and also the blender people should take a look, and see if the node system could get a bunch of the nodes used in MaPZone.
I just did a quick test in wine and its working much better than the older version, everything seems to work fine except for the 3D window where you can view the texture with all its channels and lighting.