FluxCenter ™: Your one stop Internet PHP, ASP ,custom Perl CGI programming center.

www.php.net
The Main site for the PHP project.

pear.php.net
The PEAR project where you can find handy modules for PHP .

pecl.php.net
The PECL project home of the  PHP extensions.

Zend Technologies
Founded by the authors of the Zend Engine and members of the PHP Group, Zend offers both free and commercial solutions for PHP.

alt-php-faq.org
A big FAQ and some links about PHP and SQL

de.comp.lang.php FAQ
Excellent German language FAQ about PHP

PHP Knowledge Base
Growing collection of PHP related info in a searchable question and answer format.

PHP Accelerators :
After Burner
Free open source accelerator rom Bware Technologies.

APC
Alternative Free open source accelerator available from Community Connect.

Turck MMCache for PHP
Free and open source accelerator, optimizer, encoder and dynamic content cache from TurckSoft.

EAccelerator
A fork of Turck MMCache.

ionCube PHP Accelerator
Fee accelerator available from ionCube.

Zend Accelerator
Commercial accelerator from Zend Technologies, Inc.