One of the big sources of trouble in cross-platform PHP development is the absence, presence and value of certain global (or superglobal) variables of PHP. Greatly depending on the PHP version, configuration, Web server and API used, writing cross-platform scripts without testing up in many different PHP configurations is almost impossible. e-novative has set up a free online service that collects the phpinfo output of different PHP versions and configurations on different platforms.
randomchaos.com is a fully open source website based on php/mysql. randomchaos.com includes a weblog utility, statistics tracking, a css style-chooser, and more. the source of every php page can be viewed online.
Free2Code is a large web developer community providing tutorials, downloads, developer resources, and more. Also has a irc network dedicated to helping developers.
PHPThemes aims to be the largest archive of web themes from CMS's to Forums to Image gallery's.
We will host Web Themes for most PHP Scripts (phpnuke, postnuke, xoops, phpbb, etc.)
phpPatterns is building a repository of sample software design patterns written in PHP, to help developers get the most of PHP's object oriented features. The overall aim is to raise awareness of PHP as a serious choice for enterprise level web development.