If you are talking about an editor then you can use Dreamweaver or simply notepad+. But if you are talking about server then you can use WAMPSERVER or XAMP both of these include Apache & MySQL services.
Personally I just use the php, mysql and phpmyadmin packages for linux. For my windows computer I use Wampserver, and I heard that the XAMP server is a great alternative for Macs
For editing, I like to use PHP Designer 7, this is because it's something I saw on a youtube video back when i first started learning... since then i've just become accustomed to it... to test my pages, I'm using XAMPP