PHP vs mod perl

I'm doing some research on different programming languages, and I'm looking for some help! I apologize in advance if my questions seem naiive, but I'm not a programmer, and I am approaching this from the business side of things.

I work with a company that has an existing site using mod perl to process subscriber information and a number of other high-volume items. We need to add significant new functionality quickly and we are considering using PHP. My questions are:
1) is is possible to have mod perl and PHP coexist so we do not have to re-do the work that we've already done
2) what makes PHP better than mod perl
3) are there speed issues using some of the existing web email applications such as IMP or Endymion

Thanks in advance!

PHP and mod_perl can co-exist. You can use the existing scripts without rewriting them. PHP might be siginificantly better than mod_perl for quick and dirty programming. It is siginficantly less difficult to start programming in PHP, and the syntax can be less daunting to understand. At the same time, it offers most of the functionality of Perl.