I have been known to use both. One advantage is that PHP is relatively light-weight. PHP also has very tight binding to MySQL which is good, but it's also bad as it can cause problems with mod_perl etc.

The thing that I really dislike about PHP is the variable syntax/concept (e.g. one sigil). The explosion of functions is also a little annoying.

On the plus side it has PCRE (Perl Compatible Regular Expressions ;-)

--
perl -pe "s/\b;([st])/'\1/mg"