Dev-PHP is a well-featured IDE for PHP. Fast and powerful, it is easy to use and has a lot of cool features : class browser, scripts preview, integration with PHP parsers, PHP-GTK library, and Xdebug of course. Dev-PHP-usb slips even into your pocket.
XPHP is an IDE authoring tool for Windows that allows you to design, develop, test, debug and deploy PHP applications. [This project has been discontinued since 2005]