The following are some of the popular commercial IDEs used for PHP programming.
One of the top and most powerful PHP IDEs from the PHP developers. 
Full featured PHP IDE and PHP editor for PHP code, HTML including Javascript and CSS. It is commercial. 
Easy to use PHP IDE with features include code highlighting, write faster code and quality PHP software development. PHPEd is a multi-functional PHP IDE editor for development of Css, XML and PHP including Smarty template engine. It has advanced code editor and debugger. Engsite is a complete editors and tools package for development of PHP, CSS including Perl and MySQL. It is commercial. 
Rapid PHP Editor is a powerful PHP editor with CSS editor, Javascript and PHP editor all in one package. It is commercial. 
Free IDE for PHP development. It comes with drupal plugin and highlighting for CSS, Javascript, Html and PHP.
