While this looks impressive, pystones is a little unrealistic (it's basically the old dhrystone benchmark in Python code and tests pretty much none of Python's language features). I'd be interested to see the pybench* numbers for IronPython 1.0 vs CPython 2.5 if you could...
It seems IP on mono won't run the pybench suite. Curses. I can't really have a go at fixing it... because there are no tracebacks! Egh. Looks like I've gotta play around a bit more...
-Sw