Hardened PHP
- http://www.hardened-php.net/
- Adds security hardening features to the language. Include news, libraries, Hardening patch, services advisories, a forum and a system for advanced protection of installations.
PHP Club
- http://www.phpclub.net/
- A programmer's group united by a desire to develop PHP technologies in the Internet. News, articles, applications and FAQ.
PHP: Hypertext Preprocessor
- http://www.php.net/
- Server-side HTML embedded scripting language. It provides web developers with a full suite of tools for building dynamic websites: native APIs to Apache and other web servers; easy access to MySQL, Sybase, Oracle, and other databases; IMAP; LDAP; HTTP headers and cookies.
PHPit
- http://www.phpit.net/
- PHP and MySQL articles, tutorials and codesnippets. It also has database with commonly asked questions.