Some monks have pointed to
Algorithm::Cluster which relies on the C-clustering library. Unless you have a C-compiler handy, you can simply use ppm to install a copy of
Algorithm::Cluster. Just issue
ppm install http://bonsai.ims.u-tokyo.ac.jp/~mdehoon/software/cluster/Algorithm-Cluster.ppd
CountZero
"If you have four groups working on a compiler, you'll get a 4-pass compiler." - Conway's Law