[Freddy]

Don't know if anyone already uses this but I have been meaning to drop this link in for a while.

It's a complete programming environment for the likes of PHP (which is my interest) and other stuff.  I used it a while back when I was working on the Chatterbot Collection, it's really rather nifty.

The NetBeans IDE is an award-winning integrated development environment available for Windows, Mac, Linux, and Solaris. The NetBeans project consists of an open-source IDE and an application platform that enable developers to rapidly create web, enterprise, desktop, and mobile applications using the Java platform, as well as PHP, JavaScript and Ajax, Groovy and Grails, and C/C++.
The NetBeans project is supported by a vibrant developer community and offers extensive documentation and training resources as well as a diverse selection of third-party plugins.

http://netbeans.org/

Oh and the magic word is 'Free'