I started out as a Perl programmer and recently I have picked up PHP and I have formed pretty clear notions of when to use what. For server-side scripting, I am a Perl snob through and through. In my opinion, there is no better language for doing complex (or even simple) server-side applications. However, when I want to write web applications, PHP is my choice. It's just as powerful as Perl, the syntax is similar, and it's embedded nature means that I can create complex web interfaces very quickly. It's nice to embed the language into HTML instead of having to output HTML from the language... and PHP's built-in form parsing is lovely. Basically, I say: PHP in the browser; Perl on the server. A powerful combination and all I need to do really cool things ;-)