<p>I'd be very grateful if you could compare the winning <a href="http://www.cs.ucsd.edu/~sorourke/wf.pl" rel="nofollow noreferrer">O’Rourke's Perl solution</a> to <a href="http://effbot.org/zone/wide-finder.htm" rel="nofollow noreferrer">Lundh's Python solution</a>, as I don't know Perl good enough to understand what's going on there. More specifically I'd like to know what gave Perl version 3x advantage: algorithmic superiority, quality of C extensions, other factors?</p>

<p><a href="http://www.tbray.org/ongoing/When/200x/2007/10/30/WF-Results" rel="nofollow noreferrer">Wide Finder: Results</a></p>

Perl is heavily optimized for text processing.  There are so many factors that it's hard to say what's the exact difference.  Text is represented completely differently internally (utf-8 versus utf-16/utf-32) and the regular expression engines are completely different too.  Python's regular expression engine is a custom one and not as much used as the perl one.  There are very few developers working on it (I think it's largely unmaintained) in contrast to the Perl one which is basically the "core of the language".
After all Perl is
the
text processing language.