PHP and mod_perl can co-exist perfectly. For as far as any PHP solution can be perfect. It may be a better idea to teach the guy some Perl and let him use PLP instead. In many situations, it uses less CPU/memory resources and is a bit faster.

If he really wants to use PHP, or you don't trust him with mod_perl and you both work on the same site, then PHP::Session can be a life-saver. That, and HTML/CSS templates without executable code in them. Simple variable substitution works best (and is fastest anyhow. Remember all, in many, many cases, templating toolkits are overkill) if you use several languages.

Do, however, insist that the other code in a Perl-ish manner. Foreach is so much easier to maintain than C-style for, and split/join is nicer than lots of substr and index. :)

Juerd # { site => 'juerd.nl', plp_site => 'plp.juerd.nl', do_not_use => 'spamtrap' }