You don't need to know PHP to use DolphinPro, but if you do want to know it, here's a good way to start.

DolphinPro is a PHP platform, for the most part. It's incredible how PHP, initially created as a small "hobby' language evolved into a de-facto #1 standard for web-development. It now powers estimated 40% of all websites in the world, including Facebook. So, it would be safe to say that people browse PHP-driven pages most of the time.    So, if you are