Hi, The PyPy description in getting started is still too scientific. I attach a patch with accessibility fix. =) But it is still not completely clear if PyPy's Python implementation is written in Python or in RPython? '''And the second is one particular implementation that is so generated – an implementation of the Python programming language written in Python itself.''' If Python implementation is written in Python, and not in RPython then there is the missing link between the framework and implementation, which is confusing. http://doc.pypy.org/en/latest/getting-started.html#what-is-pypy -- anatoly t.