Only available as part of the proprietary Zend Server the opcode cache and code optimizer were open sourced in mid-February. The Optimizer+ improves the performance of the PHP interpreter by optimizing the bytecode generated from PHP source files.
The proposal of integrating Zend Optimizer+ with PHP 5.5 was put up for vote through an RFC which received an overwhelming support whereby 66 out of 77 voted for the integration in general. 44 out of 70 voters were in favour of getting the Optimizer+ integrated into PHP 5.5 even if there is a minor delay.
Announcing the integration Zeev Suraski, CTO and co-founder of Zend Technologies noted, “The voting period ended, and the option selected with 44 out of 70 votes was integrating Optimizer+ into PHP 5.5.0, even at the cost of a minor delay.”
“An overwhelming majority (66 out of the 70 votes) was in favor of going with the integration in general”, he added.
Optimizer+ isn’t the only opcode cache that is available out there. There is this Alternative PHP Cache (APC) being used widely and was proposed to be included natively in PHP 6.0. The RFC notes that as compared to APC the Zend Optimizer+ is capable of handling 5 to 20 per cent more requests per second and is also better than APC when it comes to tackling erroneous cache behaviour.