Eclipse (with PHP eclipse plugin)

Eclipse Homepage: homepage

Download Eclipse: download eclipse

PHP Eclipse Homepage : homepage

PHP Eclipse Screenshots : Screenshots

PHP Eclipse User Manual : User Manual

Wikipedia: Eclipse (software)

We use the PHP Eclicpse plug in for all php website development along with the FTP plugin for uploading and subversion (SVN) to keep track of updates made in code.

The PHPEclipse User Manual details each step in the process of installing phpeclipse

Eclipse is at its core a java development tool, but the awesomeness of the php plugin makes it a great choice for php.

An excellent companion to eclipse is xampp

xampp allows you to set up a server on your computer so you can test your scripts before you upload.