IIRC a interesting case in this area was the Eric Raymond attempt to migrate GCC repository from Subversion to Git with a Python-based tool he created, called Reposurgeon. After several attempts, they gave up and ended migrating the whole tool to another language: <a href="http://esr.ibiblio.org/?p=8161" rel="nofollow">http://esr.ibiblio.org/?p=8161</a><p>In this case, the problem was less about speed and more about excessive memory load. I wonder, does the Faster CPython project also try to adress Python memory usage in addition to speed?<p>By the way, unfortunately it appears ESR stopped updating his blog. I enjoyed his technical posts.