An easily installed PHP Zend engine extension that provides a PHP cache, and is capable of delivering a substantial acceleration of PHP scripts without requiring any script changes, loss of dynamic content, or other application compromises.
www.php-accelerator.co.uk
Complete manual that explains all elements of the PHP language.
php.net/manual/en/index.php
Free PHP SQL tutorials, references, and examples for Web building. Complete references of all PHP functions. The PHP Certificate documents your knowledge of PHP and SQL (MySQL).
www.w3schools.com/php/
Open source, high-performance, distributed memory object caching system, generic in nature, but intended for use in speeding up dynamic web applications by alleviating database load.
www.memcached.org
PECL is a repository for PHP Extensions, providing a directory of all known extensions and hosting facilities for downloading and development of PHP extensions. The packaging and distribution system used by PECL is shared with its sister PEAR.
pecl.php.net
The PCRE library is a set of functions that implement regular expression pattern matching using the same syntax and semantics as Perl 5. PCRE has its own native API, as well as a set of wrapper functions that correspond to the POSIX regular ...
www.pcre.org
Requests a geo-IP-server to check, returns where an IP is located (host, state, country, town).
css-tricks.com/snippets/php/get-geo-ip-information/
A free database software tool written in PHP intended to handle the administration of MySQL over the Web. Supports a wide range of operations with MySQL.
www.phpmyadmin.net
A template engine for PHP, facilitating the separation of presentation (HTML/CSS) from application logic. This implies that PHP code is application logic, and is separated from the presentation. Feature completeness, and easily extendable to your...
www.smarty.net
A clean and classy framework for PHP web development. Freeing you from spaghetti code, Laravel helps you create wonderful applications using simple, expressive syntax.
laravel.com