Psyco, the Python specializing compiler
Psyco is a historical project and only works on Python <= 2.6 on 32-bit x86 Intel CPUs. See also PyPy.
Psyco shows that it is possible to execute Python code at speeds approaching that of fully compiled languages, by “specialization”. This extension module for the unmodified interpreter accelerates user programs with little or not change in their sources, by a factor that can be very interesting (2-10 times is common).