jpcache is a lightweight, full page caching system for PHP, thus reducing server-load, as pages are generated less often. It dramatically speeds up the serving of your pages, by caching the ouput of pages and returning them instead of compiling the php-page. It also uses gzip content-encodig and ETag-headers, which results in around 80% in traffic-saving for php-pages. You can choose to store the cached output in files in a local dir or in a database.
Turck MMCache is a opcode cache for PHP. It increases performance of PHP scripts by caching them in compiled state, so that the overhead of compiling is almost completely eliminated. Also it uses some optimizations for speed up of PHP scripts execution. Turck MMCache typically reduces server load and increases the speed of your PHP code by 1-10 times.
APC is the Alternative PHP Cache. It was conceived of to provide a free, open, and robust framework for compiling and caching php scripts. APC was conceived of to provide a way of boosting the performance of PHP on heavily loaded sites by providing a way for scripts to be cached in a compiled state, so that the overhead of parsing and compiling can be almost completely eliminated. There are commercial products which provide this functionality, but they are neither open-source nor free.
cgi_buffer is a group of libraries (for Perl, Python and PHP) that automatically handle performance-improving HTTP features that most Web servers don't implement (at least for scripts).
The Zend Optimizer is a free application that runs the files encoded by the Zend Encoder and Zend SafeGuard Suite, while enhancing the running speed of PHP applications. Benefits: Enables users to run files encoded by the Zend Encoder and increases runtime performance up to 40%.
The ionCube PHP Accelerator is 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.
