List of PHP accelerators
This is a list of PHP accelerators.
Alternative PHP Cache (APC) 
Alternative PHP Cache is a free, open source (PHP license) framework that heavily optimizes and tunes the output of the PHP bytecode compiler and stores the final, compiled result in shared memory. This bytecode optimization leads to faster runtime execution since the low-level instructions become more efficient. Its second, even more important job is maintaining a shared, in-memory bytecode cache which allows your server to re-use the compiled code rather than going through the extremely slow task of retrieving source files from disk and re-compiling them on every page load, thus giving you an even bigger performance boost. Compiled files remain in the shared cache and will only be re-compiled if the original source code files are updated. For a heavy application consisting of a large source code base such as Drupal, you can expect around a 3x increase in page generation speed as a result.
It was once the optimization framework of choice at Facebook and is extremely well suited to accelerating heavy PHP applications thanks to its mature codebase and numerous contributors (including Facebook itself). It also provides a few extra functions beyond its bytecode optimization and bytecode caching, such as giving your PHP applications the ability to store and retrieve keyed data in a global "data store" housed in shared memory, thereby allowing you to cache and significantly speed up access to very commonly used data without having to constantly go to disk or SQL backends.
Zeev Suraski and Andi Gutmans (the two creators of PHP and the Zend Engine), as well as the other major PHP developers, have decided to officially endorse APC and have scheduled it for inclusion in the PHP core no later than PHP 6. There have been discussions about including it even earlier. While this makes APC the officially endorsed PHP accelerator, they want to be clear that they still support other accelerator projects.
- Website: http://pecl.php.net/package/APC
- PHP version: works with all PHP versions up to PHP 5.4 (3.1.13 - beta release)
- Latest beta version: 3.1.13 (2012-09-03)
- Latest stable version: 3.1.9 (2011-05-14) (should only be used with PHP 4, does not support PHP 5.x)
- Status: Actively maintained (different releases stable/beta)
- Download link: http://pecl.php.net/package/APC (source code, required for up-to-date compilation)
- Official installation help: http://php.net/apc.setup and http://php.net/apc.installation (extension must be compiled against the sources of the PHP version it is to be used with; includes instructions for building on Windows)
- Pre-built Windows binaries (USE AT YOUR OWN RISK, OUTDATED AND MAY BE INCOMPATIBLE): It is always best to compile the extension yourself, but some people provide pre-built versions as a courtesy. The problem is that these versions quickly go out of date. Version 3.1.13-beta (2012-09-03) pre-compiled binaries for Windows (for PHP x86 v5.4.4, 5.4.6, 5.4.7 or 5.4.8): http://www.dragffy.com/posts/php-apc-windows. Version 3.1.10-beta (2012-04-11) pre-compiled binaries for Windows (for PHP x86? v5.3 or 5.4 threaded & non-threaded builds): http://downloads.php.net/pierre/ (also provides some other PECL extensions previously available on pecl4win)
||This section needs auditing for compliance with the Manual of Style. (February 2013)|
||This section's factual accuracy may be compromised due to out-of-date information. (February 2013)|
eAccelerator was born in December 2004 as a fork of the Turck MMCache project. Turck MMCache was created by Dmitry Stogov and much of the eAccelerator code is still based on his work. eAccelerator also contained a PHP encoder and loader, but the development staff discontinued the encoder and removed this feature after December 2006.
- Website: http://eaccelerator.net/
- PHP version: Supports PHP 4 and all PHP 5 thread-safe releases including 5.3 from version 0.9.6; breaks on 5.4. In older releases, the encoder will only work with PHP versions from the 4.x.x branch. eAccelerator will not work with any other versions of PHP. eAccelerator can only be used with the thread-safe version of PHP. (This seems not to be true, this version works for my php non-thread-safe installation: http://eac.qme.nl/eAccelerator_v1_0_svn427_for_v5_3_X-VC9.zip)
- Latest stable version: 0.9.6.1 (2010-05-31)
- Status: Potentially dead (no new releases since May 2010). UPDATE from eaccelerator.net: 25 July 2012 - Project was taken by Hans Rakers and moved to Github, master branch does support PHP 5.4
- Download link: (look for latest versions) http://eaccelerator.net/, download page on SourceForge
- Official installation help: https://eaccelerator.net/wiki/InstallFromSource
ionCube PHP Accelerator 
Launched in 2001, ionCube PHP Accelerator (PHPA) was the first freely available PHP accelerator to compete with the commercial Zend Cache product. Created before ionCube Ltd. was founded and at a time when the performance of PHP was regarded as lackluster when compared to other popular web programming languages, PHPA showed that PHP can compete with other languages performance-wise. Although the author of PHPA chose to keep the project closed source in response to early concerns raised by Zeev Suraski of Zend Technologies about the effect that an open source rival might have on their commercial alternative, the availability of PHPA on a wide variety of platforms led to its extensive adoption worldwide from small sites to Yahoo!. It also inspired the redevelopment of APC to use the shared memory execution techniques that PHPA and Zend Cache had adopted instead of deserialization on each request that incurred performance penalties.
PHPA is now discontinued and the development of a more advanced replacement has been announced.
Only supports PHP 4. No new versions on the download page since Jan. 2003.
Turck MMCache 
XCache is a fast, stable PHP opcode cacher that has been tested and is now running on production servers under high load. It is tested on Linux and FreeBSD and supported under Windows, for thread-safe and non-thread-safe versions of PHP. This relatively new opcode caching software has been developed by mOo, one of the developers of Lighttpd, to overcome some of the limitations of the existing solutions at that time; such as being able to use it with new PHP versions as they arrive.
- Website: http://xcache.lighttpd.net/
- PHP version: full support for PHP 5.4
- Latest stable version: 3.0.1 (Released on 2013-01-11)
- Status: Actively maintained (different releases stable/unstable/devel)
- Download link: http://xcache.lighttpd.net/pub/Releases/3.0.1/xcache-3.0.1.tar.gz
- Official installation help: http://xcache.lighttpd.net/wiki/InstallFromSource
Nusphere PhpExpress 
PhpExpress is a free PHP opcode cache that loads both Nu-Coder (commercial) encoded and plain PHP files directly into the PHP engine, saving loading time and boosting performance of PHP applications. It's available on Windows, Linux, FreeBSD, NetBSD, Mac OS X, and Solaris.
- Download link: http://www.nusphere.ru/files/download/NuSphere-PhpExpress-3.0.zip
- Official installation help: http://www.nusphere.com/kb/phpexpressmanual/part1.htm#2
- Website: http://www.nusphere.com/products/phpexpress.htm
Zend Opcache (ex. Zend Optimizer+) 
Zend Opcache  is an open source component of Zend Server and Zend Server Community Edition. Zend Opcache speeds up PHP execution by opcode caching and optimization. It stores precompiled script bytecode in shared memory. This eliminates the stages of reading code from the disk and compiling it on future access. For further performance improvements, the stored bytecode is optimized for faster execution. Unlike Zend Optimizer, Zend Opcache doesn't load files encoded by Zend Guard. Zend provides another component, Zend Guard Loader, in order to load encoded applications with Zend Server and Zend Server Community Edition.
Zend Optimizer+ was renamed to Zend Opcache mid of March 2013.
Starting with PHP 5.5 the Zend Opcache will be integrated and shipped with PHP.
- Website: http://pecl.php.net/package/ZendOpcache
- Sources: https://github.com/zend-dev/ZendOptimizerPlus/
- PHP version: full support for PHP 5.2+
- Latest stable version: 7.0
- Status: Actively maintained
Zend Platform 
Zend Platform (formerly Zend Cache and then Zend Accelerator) is a commercial Web Application Server product. It has a complete set of performance capabilities that includes more than a simple PHP accelerator. Features include code caching/acceleration, data caching, content (html output) caching, download optimization and off-line (asynchronous) processing capabilities that can result in significant performance improvements for most PHP applications. It also includes detailed PHP monitoring and root cause analysis support to help in tuning and debugging, session fail-over support for HA (High Availability) needs and other integration capabilities including Java integration.
Zend Platform and Zend Core are now in 'end of life' status (http://www.zend.com/en/products/platform/end-of-life) and are replaced with Zend Server .
Zend Optimizer 
Zend Optimizer is a free PHP extension created by Zend Technologies that optimizes and then caches PHP bytecode in shared memory. Additionally, it can execute Zend Guard encoded and obfuscated files.
Windows Cache Extension for PHP 
A free, open source (New BSD License), PHP accelerator developed by Microsoft for PHP under Windows. The extension includes PHP opcode cache, file cache, resolve file path cache, object/session cache, file change notifications and lock/unlock API's. Combination of all these caches results in significant performance improvements for PHP applications hosted on Windows. The extension is primarily used with Internet Information Services and non-thread-safe build of PHP via FastCGI protocol.
- Website: http://www.iis.net/expand/WinCacheForPHP
- PHP version: works with PHP 5.2 (VC6 NTS), 5.3 (VC9 NTS) and 5.4 (VC9 NTS), source code available
- Latest stable version: 1.3.4
- Status: released, actively developed.
- Download link (source): http://pecl.php.net/package/WinCache
- Download link (binary): http://www.iis.net/expand/WinCacheForPhp
- Help and API documenation http://www.php.net/wincache
Feature table 
|Name||Alive/discontinued||Opcode cache||File cache||Resolve file path cache||Object/session cache||Optimization||Cache in memory||Acceleration Low/Med/High||Source encoding|
|PHP Accelerator (PHPA)||discontinued||Yes||Yes||?||No||Yes||Yes||High||No|
|Zend Opcache (ex. Zend Optimizer+)||alive||Yes||?||?||?||Yes||Yes||High||No|
Compatibility table 
|PHP accelerators||-||OS||Web servers||PHP version|
|Alive/discontinue||Windows||Linux||FreeBSD||Mac OS X||NetBSD||Solaris||IIS 6.0||IIS 7.0||IIS 7.5||IIS 8.0||Apache 2.0||Apache 2.2||Apache 2.4||5.4||5.2|
|Zend Opcache (ex. Zend Optimizer+)||alive||Yes||?||?||?||?||No||?||?||?||?||?||?||?||Yes||Yes|
|Zend Optimizer and Zend Guard Loader||?||?||Yes||?||?||?||No||?||?||?||?||?||?||?||?||?|
See also 
- "Zend Optimizer+". Retrieved March 9, 2011.
- "ZendOptimizerPlus - GitHub". Retrieved February 13, 2013.
- "[VOTE] Integrating Zend Optimizer+ into the PHP distribution". Retrieved March 8, 2013.
- "Zend Optimizer and Zend Guard Loader". Retrieved June 22, 2011.