Redthon is the world's slowest Python implementation, written in Trefunge-98. I'll try it after PyFunge is stablized enough (and can connect to other Funge interpreter).
The first working one is expected to 2011, assuming that PyFunge 0.6.0 is due to Q3 2009. Obviously, this assumption was too optimistic. By the way, didn't you realize Redthon was a joke after all?