Persistent caching using APC, xCache, eAccelerator, Zend Disk Cache, Zend Shared Memory Cache or files.
em-object-cachedue to WP requirements ("an underscore character is not valid in a path, therefore you can't have em_object_cache as the plugin's slug. Only alphanumeric characters and the dash are valid.").
FileCacheclass methods by moving all sanity checks to
$__sjfc_optionsis forcefully global variable
$_SERVER['HTTP_HOST']is not set (CLI mode)