I hear about accelerators such as these in PHP. I believe APC is making it to PHP 6 also.
What's the state of accelerators in Zend? I see a Zend_Cache. Is it the standard and is there more?
APC and Xcache are supported via Zend_Cache_Backend_Apc and Zend_Cache_Backend_Xcache
I wanted to elaborate on the answer as APC and Xcache provide both a user cache and an opcode cache. The user cache is accessible in zend via the cache backends as mentioned above.
Re: acceleration and opcode caching, I've had good luck with running zf with Xcache/fastcgi as well as APC in both mod_php and fastcgi/fpm environments. I've heard APC is not compatible with zend optimizer so thats worth pointing out (not specific to zf). I've never used eaccelerator.
One other thing to mention is when setting up opcode caching in a fastcgi env., you are going to end up with 1 cache per cgi backend so using php-fpm is the way to go IMO.