A (biased) Pure Python Performance Comparison

The following is a performance comparison of several (pure) Python implementations, for a large part of the Shed Skin example set. I left out some of the examples, that would result in an unfair comparison (mostly because of randomization), or that were too interactive to easily measure. Obviously this comparison is very biased, and probably unfair in some way to the other projects (though I've tried to be fair, for example by letting PyPy stabilize before measuring).