Lately I have been quite in contact with Micheal Bedward, the author of the Jiffle project.
I played around a bit with it and I integrated it in the JGrass development trunk version to substitute the current mapcalc.
I will not show much here, since I created a page on the Jiffle wiki that shows some tests done so far. Just a little image to attract your attention :)
I like both Micheal and Jiffle, they are really amazing :)