1) Can you recommend me a PHP accelerator for PHP V5.2.6?
2) Do you know about any recent test comparation/review of those modules(Alternative PHP Cache, eAccelerator, XCache, Zend Optimizer, Zend Platform, ionCube PHP Accelerator, Turck MMCache, Nusphere PhpExpress)?
eAccelerator was popular, for some time it was the fastest bytecode cache. But the difference in speed is not enough to justify choosing it over APC.
Turck MMcache — dead. eAccelerator was forked from it.
ionCube — dead.
APC is pretty much the standard choice. It’s scheduled to be included in PHP 6 core. Unlike most of the other candidates, it’s stable and it’s free.
Here is a comparison of three of them, APC, Zend and XCache:
APC is easy to install, works out of the box and can be used as both an opcode cache and a data cache. Easy choice, in my opinion.