A full-featured profiler/debugger that is loaded as a zend_extension. It aims to be an analog of C's gprof or Perl's Devel::DProf. Offered from PHP.net [Open source, GPL]

A project to join PHP, which has many libs, and REP, which is powerful.

A visual frontend for debugging PHP. It runs on Win98SE and newer and can be used remotely. [Freeware]

Offers graphical front-end access to the php.ini file plus the ability to add other configuration directives, such as for the Zend optimizer or MSSQL. Windows only. [Freeware]

Software package for Windows includes an Apache server, a MySQL database, PHP 5.2.0, as well as some PHP development tools. The installation files, website and product support are also available in French and Spanish. [Freeware]

WAMP5 installs Apache, PHP5 and MySQL on Windows platform. It comes with a service manager as an icon tray and lots of options.

A combined Apache, MySQL, and PHP installer package for Windows and Linux. It supports user-defined configuration during installation including PHP as a module, PEAR, and the Zend Optimizer. The website also offers a support forum. [Freeware]

Provides an all in one solution to install Apache, PHP and MySQL on a Mac OS environment.

a Delphi-like RAD tool for PHP.

A PHP and HTML editor designed to be a lightweight and easy to use application.