gnufoo
Little Physics Engine in Haskell

Luckily for me, Chris Hecker emailed me back a copy of my Haskell port of his 2d physics example code. (I had lost my original copy in a hard drive crash.) I'm stoked. The thing that I thought impressive about the port is that it worked well in Haskell and that it was useably fast. I expected to have to do some hand coding of strict evaluations, but it never came to that even in my extended version which handles polygons of any sort or my attempt at articulated bodies. Here is the project page for physics2d.