EasyPHP is a wonderful WAMP server application. After installing it, you will have PHP 5 loaded with many useful extensions, Mysql 5.5, and Apache 2 web-server installed on your computer. This enables you to serve any PHP/Mysql driven script.
Moreover, you can have many famous content-management scripts installed with just unzipping the module on your www directory such as: WordPress, Drupal, Joomla! and SPIP, besides phpBB, the most famous forum script, and few more.
You will have a local homepage when you go to http://127.0.0.1. It will give you control over the installed Apache modules, aliases, and PHP extensions. In addition, it will enable you to access PhpMyAdmin, the famous Mysql database administration system, so you can manage your data locally or even remotely.
You can choose to run EasyPHP as a Windows service, and you can use its tray window to start or stop Apache or Mysql. The installed service will monitor any changes you do to PHP and Mysql configuration files, and automatically restart them upon any editing process.
One of the most important features is that you can install EasyPHP on any portable media such as USB drive or CD-Rom. Along with the websites developed on top of it, you can take them with you everywhere, so you can resume developing your web applications from any location.
This is why I have been using this program for years, especially because it's still being actively updated with all new packages and modules. No other competitive application is better than this one. It's even the first company to develop such functionality.