I have to deploy my php/html/css/etc code to multiple servers and i am looking at my options for software that allows easy and secure deployment to multiple servers.
I found capistrano to be very easy to use once it's setup. The configuration file can be a bit confusing at first for more complicated environments but it soon becomes worthwhile. I deploy to 14 servers on production. I also use multiple environments for deployment to a staging server. One quirk, there's a bug in Ruby that breaks parallel deployment but serially isn't too bad with svn exports.